IF YOU WOULD LIKE TO GET AN ACCOUNT, please write an
email to Administrator. User accounts are meant only to access repo
and report issues and/or generate pull requests.
This is a purpose-specific Git hosting for
BaseALT
projects. Thank you for your understanding!
Только зарегистрированные пользователи имеют доступ к сервису!
Для получения аккаунта, обратитесь к администратору.
This patch fixes mostly cluster behavior but also updates
non-cluster reaction where calls like 'lvchange -aln'
lead to incorrect errors for some segment types.
Fix the implicit activation rules where some segment types could
be activated only in exclusive mode in cluster.
lvm2 command was not preserver 'local' property and incorrectly
converted local activations in to plain exclusive, so the local
activation could have activate volumes exclusively, but remotely.
If the volume_list filters out volume from activation,
it is still success result for this function.
Change the error message back to verbose level.
Detect if the volume is active localy before zeroing,
so we report error a bit later for cases, where volume
could not be activated because it doesn't pass through volume
list (but user still could create volume when he disables
zeroing)
Add LV_TEMPORARY flag for LVs with limited existence during command
execution. Such LVs are temporary in way that they need to be activated,
some action done and then removed immediately. Such LVs are just like
any normal LV - the only difference is that they are removed during
LVM command execution. This is also the case for LVs representing
future pool metadata spare LVs which we need to initialize by using
the usual LV before they are declared as pool metadata spare.
We can optimize some other parts like udev to do a better job if
it knows that the LV is temporary and any processing on it is just
useless.
This flag is orthogonal to LV_NOSCAN flag introduced recently
as LV_NOSCAN flag is primarily used to mark an LV for the scanning
to be avoided before the zeroing of the device happens. The LV_TEMPORARY
flag makes a difference between a full-fledged LV visible in the system
and the LV just used as a temporary overlay for some action that needs to
be done on underlying PVs.
For example: lvcreate --thinpool POOL --zero n -L 1G vg
- first, the usual LV is created to do a clean up for pool metadata
spare. The LV is activated, zeroed, deactivated.
- between "activated" and "zeroed" stage, the LV_NOSCAN flag is used
to avoid any scanning in udev
- betwen "zeroed" and "deactivated" stage, we need to avoid the WATCH
udev rule, but since the LV is just a usual LV, we can't make a
difference. The LV_TEMPORARY internal LV flag helps here. If we
create the LV with this flag, the DM_UDEV_DISABLE_DISK_RULES
and DM_UDEV_DISABLE_OTHER_RULES flag are set (just like as it is
with "invisible" and non-top-level LVs) - udev is directed to
skip WATCH rule use.
- if the LV_TEMPORARY flag was not used, there would normally be
a WATCH event generated once the LV is closed after "zeroed"
stage. This will make problems with immediated deactivation that
follows.
Split image should have an out-of-sync attr ('I') - always. Even if
the RAID LV has not been written to since the LV was split off, it is
still not part of the group that makes up the RAID and is therefore
"out-of-sync".
Since the virtual snapshot has no reason to stay alive once we
detach related snapshot - deactivate whole thing in front of
snapshot removal - otherwice the code would get tricky for
support in cluster.
The correct full solution would require to have transactions
for libdm operations.
Also enable to the check for snapshot being opened prior
the origin deactivation, otherwise we could easily end
with the origin being deactivate, but snapshot still kept
active, desynchronizing locking state in cluster.
A common scenario is during new LV creation when we need to wipe the
newly created LV and avoid any udev scanning before this stage otherwise
it could cause the device (the LV) to be claimed by some other subsystem
for which there were stale metadata within LV data.
This patch adds possibility to mark the LV we're just about to wipe with
a flag that gets passed to udev via DM_COOKIE as a subsystem specific
flag - DM_SUBSYSTEM_UDEV_FLAG0 (in this case the subsystem is "LVM")
so LVM udev rules will take care of handling that.
Accept --ignoreskippedcluster with pvs, vgs, lvs, pvdisplay, vgdisplay,
lvdisplay, vgchange and lvchange to avoid the 'Skipping clustered
VG' errors when requesting information about a clustered VG
without using clustered locking and still exit with success.
The messages can still be seen with -v.
lib/metadata/lv_manip.c:_sufficient_pes_free() was calculating the
required space for RAID allocations incorrectly due to double
accounting. This resulted in failure to allocate when available
space was tight.
When RAID data and metadata areas are allocated together, the total
amount is stored in ah->new_extents and ah->alloc_and_split_meta is
set. '_sufficient_pes_free' was adding the necessary metadata extents
to ah->new_extents without ever checking ah->alloc_and_split_meta.
This often led to double accounting of the metadata extents. This
patch checks 'ah->alloc_and_split_meta' to perform proper calculations
for RAID.
This error is only present in the function that checks for the needed
space, not in the functions that do the actual allocation.
If "default" thin pool chunk size calculation method is selected,
use minimum_io_size, otherwise optimal_io_size for "performance"
device hint exposed in sysfs. If there appear to be PVs with
different hints presented, use their least common multiple.
If the hint is less than the default value defined for the
calculation method, use the default value instead.
A previous commit (b6bfddcd0a) which
was designed to prevent segfaults during lvextend when trying to
extend striped logical volumes forgot to include calculations for
RAID4/5/6 parity devices. This was causing the 'contiguous' and
'cling_by_tags' allocation policies to fail for RAID 4/5/6.
The solution is to remember that while we can compare
ah->area_count == prev_lvseg->area_count
for non-RAID, we should compare
(ah->area_count + ah->parity_count) == prev_lvseg->area_count
for a general solution.
Older gcc is giving misleading warning:
metadata/lv_manip.c:4018: warning: ‘seg’ may be used uninitialized in
this function
But warning free compilation is better.
Creation, deletion, [de]activation, repair, conversion, scrubbing
and changing operations are all now available for RAID LVs in a
cluster - provided that they are activated exclusively.
The code has been changed to ensure that no LV or sub-LV activation
is attempted cluster-wide. This includes the often overlooked
operations of activating metadata areas for the brief time it takes
to clear them. Additionally, some 'resume_lv' operations were
replaced with 'activate_lv_excl_local' when sub-LVs were promoted
to top-level LVs for removal, clearing or extraction. This was
necessary because it forces the appropriate renaming actions the
occur via resume in the single-machine case, but won't happen in
a cluster due to the necessity of acquiring a lock first.
The *raid* tests have been updated to allow testing in a cluster.
For the most part, this meant creating devices with '-aey' if they
were to be converted to RAID. (RAID requires the converting LV to
be EX because it is a condition of activation for the RAID LV in
a cluster.)
When images and their associated metadata are removed from a RAID1 LV,
the remaining sub-LVs are "shifted" down to fill the gaps. For
example, if there is a 3-way mirror:
[0][1][2]
and we remove device#0, the devices will be shifted down
[1][2]
and renamed.
[0][1]
This can create a problem for resume_lv (specifically,
dm_tree_activate_children) during the renaming process though. This
is because it will attempt to rename the higher indexed sub-LVs first
and find that it cannot because there are currently other sub-LVs with
that name. The solution is to check for a conflicting name before
attempting to rename. If a conflict is found and that conflicting
sub-LV is also in the process of renaming, we can defer the current
rename until the conflicting sub-LV has renamed and cleared the
conflict.
Now that resume_lv can handle these types of rename conflicts, we can
remove the workaround in RAID that was attempting to resume a RAID1
LV from the bottom-up in order to force a proper rename in assending
order before attempting a resume on the top-level LV. This "hack"
only worked for single machine use-cases of LVM. Clearing this up
paves the way for exclusive activation of RAID LVs in a cluster.
When the pool is created from non-linear target the more complex rules
have to be used and stacking needs to properly decode args for _tdata
LV. Also proper allocation policies are being used according to those
set in lvm2 metadata for data and metadata LVs.
Also properly check for active pool and extra code to active it
temporarily.
With this fix it's now possible to use:
lvcreate -L20 -m2 -n pool vg --alloc anywhere
lvcreate -L10 -m2 -n poolm vg --alloc anywhere
lvconvert --thinpool vg/pool --poolmetadata vg/poolm
lvresize -L+10 vg/pool
The pool metadata LV must be accounted for when determining what PVs
are in a thin-pool. The pool LV must also be accounted for when
checking thin volumes.
This is a prerequisite for pvmove working with thin types.
The function 'get_pv_list_for_lv' will assemble all the PVs that are
used by the specified LV. It uses 'for_each_sub_lv' to traverse all
of the sub-lvs which may compose it.
When creating a new thin pool and there's no profile requested
via "lvcreate --profile ...", inherit any VG profile if it's attached.
Currently this applies to these settings:
allocation/thin_pool_chunk_size
allocation/thin_pool_discards
allocation/thin_pool_zero
The PREFERRED allocation mechanism requires the number of areas in the
previous LV segment to match the number in the new segment being
allocated. If they do not match, the code may crash.
E.g. https://bugzilla.redhat.com/989347
Introduce A_AREA_COUNT_MATCHES and when not set avoid referring
to the previous segment with the contiguous and cling policies.
commit d00d45a8b6 introduced changes
that are causing cluster mirror tests to fail. Ultimately, I think
the change was right, but a proper clean-up will have to wait.
The portion of the commit we are reverting correlates to the
following commit comment:
2) lib/metadata/mirror.c:_delete_lv() - should have been calling
_activate_lv_like_model() with 'mirror_lv'. This is because
'mirror_lv' is the LV that the overall operation is being
performed on. We need to use this LV as the basis for
determining whether to activate locally, or across the
cluster, etc.
It appears that when legs or logs are removed from a mirror, they
are being activated before they are deleted in order to make them
top-level LVs that can be acted upon. When doing this, it appears
they are not activated based on the characteristics of the mirror
from which they came. IOW, if the mirror was exclusively active,
the sub-LVs are activated globally. This is a no-no. This then
made it impossible to activate_lv_like_model if the model was
"mirror_lv" instead of "lv" in _delete_lv(). Thus, at some point
this change should probably be put back and those location where
the sub-LVs are being improperly activated "shared" instead of
EX should be corrected.
Three fixme's addressed in this commit:
1) lib/metadata/lv_manip.c:_calc_area_multiple() - this could be
safely changed to a comment explaining that currently because
RAID10 can only have a 2-way mirror, we don't need to know the
number of stripes. However, we will need to know that in the
future if RAID10 is to support more than 2-way mirroring.
2) lib/metadata/mirror.c:_delete_lv() - should have been calling
_activate_lv_like_model() with 'mirror_lv'. This is because
'mirror_lv' is the LV that the overall operation is being
performed on. We need to use this LV as the basis for
determining whether to activate locally, or across the
cluster, etc.
3) tools/lvcreate.c:_lvcreate_params() - Minor clean-up. If
'-m 0' is given, treat it as though the mirroring argument
was not given (i.e. as though the requested segment type
was 'stripe' and not mirror).
Activation is needed only for clustered VG.
For non-clustered VG skip activation, since deactivate_lv()
is called without problems (no testing for lock presence).
(updates f6ded62291)
When the merging of snapshot is finished, we need to clean dm table
intries for snapshot and -cow device. So for merging snapshot
we have to activate_lv plain 'cow' LV and let the table
resolver to its work - shortly deactivation_lv() request
will follow - in cluster this needs LV lock to be held by clvmd.
Also update a test - add small wait - if lvremove is not 'fast enough'
and merging process has not been stopped and $lv1 removed in background.
Ortherwise the following lvcreate occasionally finds name $lv1 still in use.
(in release fix)
Add --poolmetadataspare option and creates and handles
pool metadata spare lv when thin pool is created.
With default setting 'y' it tries to ensure, spare has
at least the size of created LV.
Pool creation involves clearing of metadata device
which triggers udev watch rule we cannot udev synchronize with
in current code.
This metadata devices needs to be activated localy,
so in cluster mode deactivation and reactivation
is always needed.
However for non-clustered mode we may reload table
via suspend/resume path which avoids collision with
udev watch rule which was occasionaly triggering
retry deactivation loop.
Code has been also split into 2 separate code paths
for thin pools and thin volumes which improved readability
of the code as well.
Deactivation has been moved out of extend_pool() and
decision is now in _lv_create_an_lv() which knows
the change mode.
Since we vg_write&commit metadata LV inside lv_extend() call,
proper restore is needed in case something fails.
So add bad: section which deactivates activated LV
and removes it from VG.
Also check early for metadata LV name lengh fail.
Remove backup() call from update_pool_lv() as it's been there
duplicated and preperly order backup() call after lvresize,
so there is just one such call.
If the thin pool is known to be active, messages can be passed
to the pool even when the created thin volume is not going to be
activated.
So we do not need to stack large list of message and validate
and catch creation errors earlier in this case.
Replace the test for valid activation combination with simpler list of
deactivation combinations.
The activation/auto_set_activation_skip enables/disables automatic
adding of the ACTIVATION_SKIP LV flag. By default thin snapshots
are flagged to be skipped during activation.
And by default, the auto_set_activation_skip is enabled.
Also add -k/--setactivationskip y/n and -K/--ignoreactivationskip
options to lvcreate.
The --setactivationskip y sets the flag in metadata for an LV to
skip the LV during activation. Also, the newly created LV is not
activated.
Thin snapsots have this flag set automatically if not specified
directly by the --setactivationskip y/n option.
The --ignoreactivationskip overrides the activation skip flag set
in metadata for an LV (just for the run of the command - the flag
is not changed in metadata!)
A few examples for the lvcreate with the new options:
(non-thin snap LV => skip flag not set in MDA + LV activated)
raw/~ $ lvcreate -l1 vg
Logical volume "lvol0" created
raw/~ $ lvs -o lv_name,attr vg/lvol0
LV Attr
lvol0 -wi-a----
(non-thin snap LV + -ky => skip flag set in MDA + LV not activated)
raw/~ $ lvcreate -l1 -ky vg
Logical volume "lvol1" created
raw/~ $ lvs -o lv_name,attr vg/lvol1
LV Attr
lvol1 -wi------
(non-thin snap LV + -ky + -K => skip flag set in MDA + LV activated)
raw/~ $ lvcreate -l1 -ky -K vg
Logical volume "lvol2" created
raw/~ $ lvs -o lv_name,attr vg/lvol2
LV Attr
lvol2 -wi-a----
(thin snap LV => skip flag set in MDA (default behaviour) + LV not activated)
raw/~ $ lvcreate -L100M -T vg/pool -V 1T -n thin_lv
Logical volume "thin_lv" created
raw/~ $ lvcreate -s vg/thin_lv -n thin_snap
Logical volume "thin_snap" created
raw/~ $ lvs -o name,attr vg
LV Attr
pool twi-a-tz-
thin_lv Vwi-a-tz-
thin_snap Vwi---tz-
(thin snap LV + -K => skip flag set in MDA (default behaviour) + LV activated)
raw/~ $ lvcreate -s vg/thin_lv -n thin_snap -K
Logical volume "thin_snap" created
raw/~ $ lvs -o name,attr vg/thin_lv
LV Attr
thin_lv Vwi-a-tz-
(thins snap LV + -kn => no skip flag in MDA (default behaviour overridden) + LV activated)
[0] raw/~ # lvcreate -s vg/thin_lv -n thin_snap -kn
Logical volume "thin_snap" created
[0] raw/~ # lvs -o name,attr vg/thin_snap
LV Attr
thin_snap Vwi-a-tz-
Start separating the validation from the action in the basic lvresize
code moved to the library.
Remove incorrect use of command line error codes from lvresize library
functions. Move errors.h to tools directory to reinforce this,
exporting public versions of the error codes in lvm2cmd.h for dmeventd
plugins to use.
Fix and improve handling on sigint.
Always check for signal presence *before* calling of command,
so it will not call the command when break was hit.
If the command has been finished succesfully there is
no problem to mark the command ok and not report interrupt at all.
Fix cuple related stack; reports and assignments.
The pv resize code required that a lvm_vg_write be done
to commit the change. When the method to add the ability
to list all PVs, including ones that are not assocated with
a VG we had no way for the user to make the change persistent.
Thus additional resize code was move and now liblvm calls into
a resize function that does indeed write the changes out, thus
not requiring the user to explicitly write out he changes.
Signed-off-by: Tony Asleson <tasleson@redhat.com>
Code move and changes to support calling code from
command line and from library interface.
V2 Change lock_vol call
Signed-off-by: Tony Asleson <tasleson@redhat.com>
As locks are held, you need to call the included function
to release the memory and locks when done transversing the
list of physical volumes.
V2: Rebase fix
V3: Prevent VGs from getting cached and then write protected.
Signed-off-by: Tony Asleson <tasleson@redhat.com>
Simplified version of lv resize.
v3: Rebase changes to make work. Needed to set sizeargs = 1
to indicate to resize that we are asking for a size based
resize.
Signed-off-by: Tony Asleson <tasleson@redhat.com>
These settins are customizable by profiles:
allocation/thin_pool_zero
allocation/thin_pool_discards
allocation/thin_pool_chunk_size
activation/thin_pool_autoextend_threshold
activation/thin_pool_autoextend_percent
If "vgcreate/lvcreate --profile <profile_name>" is used, the profile
name is automatically stored in metadata for making it possible to
load it automatically next time the VG/LV is used.
This is per VG/LV profile loading on demand. The profile itself is saved
in struct volume_group/logical_volume as "profile" field so we can
reference it whenever needed.
Do not keep multiple archives for the executed command.
Reuse the ALLOCATABLE_PV from pv status for
ARCHIVED_VG vg status. Mark VG with the bit with the
first archivation.
Since reduce the message has informational character and doesn't lead
to exit of the command - reduce the log level to info print as we
use for other similar types.
Reindent next print message.
Changes:
- move device type registration out of "type filter" (filter.c)
to a separate and new dev-type.[ch] for common use throughout the code
- the structure for keeping the major numbers detected for available
device types and available partitioning available is stored in
"dev_types" structure now
- move common partitioning detection code to dev-type.[ch] as well
together with other device-related functions bound to dev_types
(see dev-type.h for the interface)
The dev-type interface contains all common functions used to detect
subsystems/device types, signature/superblock recognition code,
type-specific device properties and other common device properties
(bound to dev_types), including partitioning support.
- add dev_types instance to cmd context as cmd->dev_types for common use
- use cmd->dev_types throughout as a central point for providing
information about device types
Giving volume type information about being 'metadata' type of volume
has higher priority then i.e. 'mirror' or 'thin' flag - for those
type we have 'target attr' (7th. field).
The special suspend/resume code in lv_remove for LVM1 snapshots was interpsersed
with a vg_commit call. However, while with LVM1 metadata, vg_commit is
technically a no-op, the activation code relied on the ondisk and incore
metadata being the same, since on LVM1, a "commit" happens in vg_write
already. Since the "ondisk" metadata was previously not available with format1
(and incore was silently used instead, via lvmcache), the problem was masked.
Previously, we have relied on UUIDs alone, and on lvmcache to make getting a
"new copy" of VG metadata fast. If the code which triggers the activation has
the correct VG metadata at hand (the version which is currently on disk), it can
now hand it to the activation code directly.
This allows us to get the current on-disk version of the metadata whenever we
have the current in-flight version, without a recourse to scanning or lvmcache.
This patch adds the ability to set the minimum and maximum I/O rate for
sync operations in RAID LVs. The options are available for 'lvcreate' and
'lvchange' and are as follows:
--minrecoveryrate <Rate> [bBsSkKmMgG]
--maxrecoveryrate <Rate> [bBsSkKmMgG]
The rate is specified in size/sec/device. If a suffix is not given,
kiB/sec/device is assumed. Setting the rate to 0 removes the preference.
There is no point in creation of 2chunks snapshot,
since the snapshot is invalidated immeditelly with the first write
as there is no free chunk for COW blocks
(2 chunks are used by the snap header and the 1st. metadata chunk).
Enhance error message about the lowest usable size.
Avoid hitting memory corruption (double free) in code path,
where PV FID has been already destroyed and the released pointer
was left in PV structure and could have been tried to be released
from there 2nd. time with final context destruction.
There are places where 'lv_is_active' was being used where it was
more correct to use 'lv_is_active_locally'. For example, when checking
for the existance of a kernel instance before asking for its status.
Most of the time these would work correctly. (RAID is only allowed on
non-clustered VGs at the moment, which means that 'lv_is_active' and
'lv_is_active_locally' would give the same result.) However, it is
more correct to use the proper variant and it helps with future
scenarios where targets might be allowed exclusively (or clustered) in
a cluster VG.
This fixes a long standing regression since LVM2 2.02.74 (commit 4efb1d9c,
"Update heuristic used for default and detected data alignment.")
The default PE alignment could be used (via MAX()) even if it was
determined that the device's MD stripe width, or minimal_io_size or
optimal_io_size were not factors of the default PE alignment (either 64K
or the newer default of 1MB, etc). This bug would manifest if the
default PE alignment was larger than the overriding hint that the
device provided (e.g. default of 1MB vs optimal_io_size of 768K).
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
For reporting stacked or joined devices properly in cluster,
we need to report their activation state according the lock,
which activated this device tree.
This is getting a bit complex - current code tries simple approach -
For snapshot - return status for origin.
For thin pool - return status of the first known active thin volume.
For the rest of them - try to use dependency list of LVs and skip
known execptions. This should be able to recursively deduce top level
device for given LV.
(in release fix)
Add new lvs segment field 'Monitor' showing 3 states:
"monitored" - LV is monitored by dmeventd.
"not monitored" - LV is currently not being monitored by dmeventd
"" (empty) - LV does not support monitoring, or dmeventd support
is not compiled in.
Support for exclusive activation of snapshots revealed some problems.
When snapshot is created, COW LV is activated first (for clearing) and
then it's transformed into snapshot's COW LV, but it has left the lock
for such LV active in cluster and this lock could not have been removed
from dlm, unless snapshot has been removed within same dlm session.
If the user tried to remove snapshot after rebooting node, the lock was
missing, and COW LV could not have been detached.
Patch modifes the approach in this way:
Always deactivate COW LV for clustered vg after clearing (so it's
activated again via imlicit snapshot activation rule when snapshot is activated).
When snapshot is removed, activate COW LV as independend LV, so the lock
will exist for such LV, but only when the snapshot is active.
Also add test case for testing snapshot removal after cluster reboot.
'lvchange' is used to alter a RAID 1 logical volume's write-mostly and
write-behind characteristics. The '--writemostly' parameter takes a
PV as an argument with an optional trailing character to specify whether
to set ('y'), unset ('n'), or toggle ('t') the value. If no trailing
character is given, it will set the flag.
Synopsis:
lvchange [--writemostly <PV>:{t|y|n}] [--writebehind <count>] vg/lv
Example:
lvchange --writemostly /dev/sdb1:y --writebehind 512 vg/raid1_lv
The last character in the 'lv_attr' field is used to show whether a device
has the WriteMostly flag set. It is signified with a 'w'. If the device
has failed, the 'p'artial flag has priority.
Example ("nosync" raid1 with mismatch_cnt and writemostly):
[~]# lvs -a --segment vg
LV VG Attr #Str Type SSize
raid1 vg Rwi---r-m 2 raid1 500.00m
[raid1_rimage_0] vg Iwi---r-- 1 linear 500.00m
[raid1_rimage_1] vg Iwi---r-w 1 linear 500.00m
[raid1_rmeta_0] vg ewi---r-- 1 linear 4.00m
[raid1_rmeta_1] vg ewi---r-- 1 linear 4.00m
Example (raid1 with mismatch_cnt, writemostly - but failed drive):
[~]# lvs -a --segment vg
LV VG Attr #Str Type SSize
raid1 vg rwi---r-p 2 raid1 500.00m
[raid1_rimage_0] vg Iwi---r-- 1 linear 500.00m
[raid1_rimage_1] vg Iwi---r-p 1 linear 500.00m
[raid1_rmeta_0] vg ewi---r-- 1 linear 4.00m
[raid1_rmeta_1] vg ewi---r-p 1 linear 4.00m
A new reportable field has been added for writebehind as well. If
write-behind has not been set or the LV is not RAID1, the field will
be blank.
Example (writebehind is set):
[~]# lvs -a -o name,attr,writebehind vg
LV Attr WBehind
lv rwi-a-r-- 512
[lv_rimage_0] iwi-aor-w
[lv_rimage_1] iwi-aor--
[lv_rmeta_0] ewi-aor--
[lv_rmeta_1] ewi-aor--
Example (writebehind is not set):
[~]# lvs -a -o name,attr,writebehind vg
LV Attr WBehind
lv rwi-a-r--
[lv_rimage_0] iwi-aor-w
[lv_rimage_1] iwi-aor--
[lv_rmeta_0] ewi-aor--
[lv_rmeta_1] ewi-aor--
New options to 'lvchange' allow users to scrub their RAID LVs.
Synopsis:
lvchange --syncaction {check|repair} vg/raid_lv
RAID scrubbing is the process of reading all the data and parity blocks in
an array and checking to see whether they are coherent. 'lvchange' can
now initaite the two scrubbing operations: "check" and "repair". "check"
will go over the array and recored the number of discrepancies but not
repair them. "repair" will correct the discrepancies as it finds them.
'lvchange --syncaction repair vg/raid_lv' is not to be confused with
'lvconvert --repair vg/raid_lv'. The former initiates a background
synchronization operation on the array, while the latter is designed to
repair/replace failed devices in a mirror or RAID logical volume.
Additional reporting has been added for 'lvs' to support the new
operations. Two new printable fields (which are not printed by
default) have been added: "syncaction" and "mismatches". These
can be accessed using the '-o' option to 'lvs', like:
lvs -o +syncaction,mismatches vg/lv
"syncaction" will print the current synchronization operation that the
RAID volume is performing. It can be one of the following:
- idle: All sync operations complete (doing nothing)
- resync: Initializing an array or recovering after a machine failure
- recover: Replacing a device in the array
- check: Looking for array inconsistencies
- repair: Looking for and repairing inconsistencies
The "mismatches" field with print the number of descrepancies found during
a check or repair operation.
The 'Cpy%Sync' field already available to 'lvs' will print the progress
of any of the above syncactions, including check and repair.
Finally, the lv_attr field has changed to accomadate the scrubbing operations
as well. The role of the 'p'artial character in the lv_attr report field
as expanded. "Partial" is really an indicator for the health of a
logical volume and it makes sense to extend this include other health
indicators as well, specifically:
'm'ismatches: Indicates that there are discrepancies in a RAID
LV. This character is shown after a scrubbing
operation has detected that portions of the RAID
are not coherent.
'r'efresh : Indicates that a device in a RAID array has suffered
a failure and the kernel regards it as failed -
even though LVM can read the device label and
considers the device to be ok. The LV should be
'r'efreshed to notify the kernel that the device is
now available, or the device should be 'r'eplaced
if it is suspected of failing.
The pv_by_path might be also dangerous to use as it does not
count with any other metadata areas but the ones found on the PV
itself. If metadata was not found on the PV referenced by the path,
it returned no PV though it might have been referenced by metadata
elsewhere (on other PVs...).
If extending a VG and including a PV with 0 MDAs that was already
a part of a VG, the vgextend allowed that PV to be added and we
ended up *with one PV in two VGs*!
The vgextend code used the 'pv_by_path' fn that returned a PV for
a given path. However, when the PV did not have any metadata areas,
the fn just returned a PV without any reference to existing VG.
Consequently, any checks for the existing VG failed.
[0] raw/~ # pvcreate --metadatacopies 0 /dev/sda
Physical volume "/dev/sda" successfully created
[0] raw/~ # pvcreate --metadatacopies 1 /dev/sdb
Physical volume "/dev/sdb" successfully created
[0] raw/~ # vgcreate vg1 /dev/sda /dev/sdb
Volume group "vg1" successfully created
[0] raw/~ # pvcreate --metadatacopies 1 /dev/sdc
Physical volume "/dev/sdc" successfully created
[0] raw/~ # vgcreate vg2 /dev/sdc
Volume group "vg2" successfully created
Before this patch (incorrect):
[0] raw/~ # vgextend vg2 /dev/sda
Volume group "vg2" successfully extended
With this patch (correct):
[0] raw/~ # vgextend vg2 /dev/sda
Physical volume '/dev/sda' is already in volume group 'vg1'
Unable to add physical volume '/dev/sda' to volume group 'vg2'.
Before, the find_pv_by_name call always failed if the PV found was orphan.
However, we might use this function even for a PV that is not part of any VG.
This patch adds 'allow_orphan' arg to find_pv_by_name fn that allows that.
_find_pv_by_name -> find_pv_by_name
_find_pv_in_vg -> find_pv_in_vg
_find_pv_in_vg_by_uuid -> find_pv_in_vg_by_uuid
The only callers of the underscored variants were their wrappers
without the underscore. No other part of the code referenced the
underscored variants.
Keep the flag whether given thin pool argument has been given on command
line or it's been 'estimated'
Call of update_pool_params() must not change cmdline given args and
needs to know this info.
Since there is a need to move this update function into /lib, we cannot
use arg_count().
FIXME: we need some generic mechanism here.
For example, the old call and reference:
find_config_tree_str(cmd, "devices/dir", DEFAULT_DEV_DIR)
...now becomes:
find_config_tree_str(cmd, devices_dir_CFG)
So we're referring to the named configuration ID instead
of passing the configuration path and the default value
is taken from central config definition in config_settings.h
automatically.
The PV header extension information (PV header extension version, flags
and list of Embedding Area locations) is stored just beyond the PV header base.
When calculating the Embedding Area start value (ea_start), the same logic is
used as when calculating the pe_start value for Data Area - the value must
follow exactly the same alignment restrictions for its start value
(the alignment detected automatically or provided via command line using
the --dataalignment and --dataalignmentoffset arguments).
The Embedding Area is placed at the very start of the PV, starting at
ea_start. The Data Area starting at pe_start is placed next. The pe_start is
still properly aligned. Due to the pe_start alignment, it's possible that the
resulting Embedding Area size (ea_size) ends up bigger in size than requested
(but never less than requested).
New tools with PV header extension support will read the extension
if it exists and it's not an error if it does not exist (so old PVs
will still work seamlessly with new tools).
Old tools without PV header extension support will just ignore any
extension.
As for the Embedding Area location information (its start and size),
there are actually two places where this is stored:
- PV header extension
- VG metadata
The VG metadata contains a copy of what's written in the PV header
extension about the Embedding Area location (NULL value is not copied):
physical_volumes {
pv0 {
id = "AkSSRf-difg-fCCZ-NjAN-qP49-1zzg-S0Fd4T"
device = "/dev/sda" # Hint only
status = ["ALLOCATABLE"]
flags = []
dev_size = 262144 # 128 Megabytes
pe_start = 67584
pe_count = 23 # 92 Megabytes
ea_start = 2048
ea_size = 65536 # 32 Megabytes
}
}
The new metadata fields are "ea_start" and "ea_size".
This is mostly useful when restoring the PV by using existing
metadata backups (e.g. pvcreate --restorefile ...).
New tools does not require these two fields to exist in VG metadata,
they're not compulsory. Therefore, reading old VG metadata which doesn't
contain any Embedding Area information will not end up with any kind
of error but only a debug message that the ea_start and ea_size values
were not found.
Old tools just ignore these extra fields in VG metadata.
PV header extension comes just beyond the existing PV header base:
PV header base (existing):
- uuid
- device size
- null-terminated list of Data Areas
- null-terminater list of MetaData Areas
PV header extension:
- extension version
- flags
- null-terminated list of Embedding Areas
This patch also adds "eas" (Embedding Areas) list to lvmcache (lvmcache_info)
and it also adds support for common operations on the list (just like for
already existing "das" - Data Areas list):
- lvmcache_add_ea
- lvmcache_update_eas
- lvmcache_foreach_ea
- lvmcache_del_eas
Also, add ea_start and ea_size to struct physical_volume for processing
PV Embedding Area location throughout the code (currently only one
Embedding Area is supported, though the definition on disk allows for
more if needed in the future...).
Also, define FMT_EAS format flag to mark that the format actually
supports Embedding Areas (currently format-text only).
Extract restorable PV creation parameters from struct pvcreate_params into
a separate struct pvcreate_restorable_params for clarity and also for better
maintainability when adding any new items later.
Use the field 'origin' for reporting external origin lv name.
For thin volumes with external origin, report the size of
external origin size via:
lvs -o+origin_size
If zero metadata copies are used, there's no further recalculation of
PV alignment that happens when adding metadata areas to the PV and
which actually calculates the alignment correctly as a matter of fact.
So fix this for "PV without MDA" case as well.
Before this patch:
[1] raw/~ # pvcreate --dataalignment 8m --dataalignmentoffset 4m
--metadatacopies 1 /dev/sda
Physical volume "/dev/sda" successfully created
[1] raw/~ # pvs -o pv_name,pe_start
PV 1st PE
/dev/sda 12.00m
[1] raw/~ # pvcreate --dataalignment 8m --dataalignmentoffset 4m
--metadatacopies 0 /dev/sda
Physical volume "/dev/sda" successfully created
[1] raw/~ # pvs -o pv_name,pe_start
PV 1st PE
/dev/sda 8.00m
After this patch:
[1] raw/~ # pvcreate --dataalignment 8m --dataalignmentoffset 4m
--metadatacopies 1 /dev/sda
Physical volume "/dev/sda" successfully created
[1] raw/~ # pvs -o pv_name,pe_start
PV 1st PE
/dev/sda 12.00m
[1] raw/~ # pvcreate --dataalignment 8m --dataalignmentoffset 4m
--metadatacopies 0 /dev/sda
Physical volume "/dev/sda" successfully created
[1] raw/~ # pvs -o pv_name,pe_start
PV 1st PE
/dev/sda 12.00m
Also, remove a superfluous condition "pv->pe_start < pv->pe_align" in:
if (pe_start == PV_PE_START_CALC && pv->pe_start < pv->pe_align)
pv->pe_start = pv->pe_align ...
This part of the condition is not reachable as with the PV_PE_START_CALC,
we always have pv->pe_start set to 0 from the PV struct initialisation
(...the pv->pe_start value is just being calculated).
When a device fails, we may wish to replace those segments with an
error segment. (Like when a 'vgreduce --removemissing' removes a
failed device that happens to be a RAID image/meta.) We are then left
with images that we will eventually want to remove or replace.
This patch allows us to pull out these virtual "error" sub-LVs. This
allows a user to 'lvconvert -m -1 vg/lv' to extract the bad sub-LVs.
Sub-LVs with error segments are considered for extraction before other
possible devices so that good devices are not accidentally removed.
This patch also adds the ability to replace RAID images that contain error
segments. The user will still be unable to run 'lvconvert --replace'
because there is no way to address the 'error' segment (i.e. no PV
that it is associated with). However, 'lvconvert --repair' can be
used to replace the image's error segment with a new PV. This is also
the most appropriate way to do it, since the LV will continue to be
reported as 'partial'.
Currently it is impossible to remove a failed PV which has a RAID LV
on it. This patch fixes the issue by replacing the failed PV with an
'error' segment within the affected sub-LVs. Once there is no longer
a RAID LV using the PV, it can be removed.
Most often, it is better to replace a failed RAID device with a spare.
(You can use 'lvconvert --repair <vg>/<LV>' to accomplish that.)
However, if there are no spares in the volume group and none will be
added, it is useful to be able to removed the failed device.
Following patches address the ability to perform 'lvconvert' operations
on RAID LVs that contain sub-LVs composed of 'error' segments.
We have been using 'mirror_region_size' in lvm.conf as the default region
size for RAID logical volumes as well as mirror logical volumes. Since,
"raid" is more inclusive and representative than "mirror", I have changed
the name of this setting. We must still check for the old setting and warn
the user if we are overriding it with the new setting if both happen to be
present.
This internal function check for active pool device.
For cluster it checks every thin volume,
On the non-clustered VG we need to check just
for presence of -tpool device.
There are currently a few issues with the reporting done on RAID LVs and
sub-LVs. The most concerning is that 'lvs' does not always report the
correct failure status of individual RAID sub-LVs (devices). This can
occur when a device fails and is restored after the failure has been
detected by the kernel. In this case, 'lvs' would report all devices are
fine because it can read the labels on each device just fine.
Example:
[root@bp-01 lvm2]# lvs -a -o name,vg_name,attr,copy_percent,devices vg
LV VG Attr Cpy%Sync Devices
lv vg rwi-a-r-- 100.00 lv_rimage_0(0),lv_rimage_1(0)
[lv_rimage_0] vg iwi-aor-- /dev/sda1(1)
[lv_rimage_1] vg iwi-aor-- /dev/sdb1(1)
[lv_rmeta_0] vg ewi-aor-- /dev/sda1(0)
[lv_rmeta_1] vg ewi-aor-- /dev/sdb1(0)
However, 'dmsetup status' on the device tells us a different story:
[root@bp-01 lvm2]# dmsetup status vg-lv
0 1024000 raid raid1 2 DA 1024000/1024000
In this case, we must also be sure to check the RAID LVs kernel status
in order to get the proper information. Here is an example of the correct
output that is displayed after this patch is applied:
[root@bp-01 lvm2]# lvs -a -o name,vg_name,attr,copy_percent,devices vg
LV VG Attr Cpy%Sync Devices
lv vg rwi-a-r-p 100.00 lv_rimage_0(0),lv_rimage_1(0)
[lv_rimage_0] vg iwi-aor-p /dev/sda1(1)
[lv_rimage_1] vg iwi-aor-- /dev/sdb1(1)
[lv_rmeta_0] vg ewi-aor-p /dev/sda1(0)
[lv_rmeta_1] vg ewi-aor-- /dev/sdb1(0)
The other case where 'lvs' gives incomplete or improper output is when a
device is replaced or added to a RAID LV. It should display that the RAID
LV is in the process of sync'ing and that the new device is the only one
that is not-in-sync - as indicated by a leading 'I' in the Attr column.
(Remember that 'i' indicates an (i)mage that is in-sync and 'I' indicates
an (I)mage that is not in sync.) Here's an example of the old incorrect
behaviour:
[root@bp-01 lvm2]# lvs -a -o name,vg_name,attr,copy_percent,devices vg
LV VG Attr Cpy%Sync Devices
lv vg rwi-a-r-- 100.00 lv_rimage_0(0),lv_rimage_1(0)
[lv_rimage_0] vg iwi-aor-- /dev/sda1(1)
[lv_rimage_1] vg iwi-aor-- /dev/sdb1(1)
[lv_rmeta_0] vg ewi-aor-- /dev/sda1(0)
[lv_rmeta_1] vg ewi-aor-- /dev/sdb1(0)
[root@bp-01 lvm2]# lvconvert -m +1 vg/lv; lvs -a -o name,vg_name,attr,copy_percent,devices vg
LV VG Attr Cpy%Sync Devices
lv vg rwi-a-r-- 0.00 lv_rimage_0(0),lv_rimage_1(0),lv_rimage_2(0)
[lv_rimage_0] vg Iwi-aor-- /dev/sda1(1)
[lv_rimage_1] vg Iwi-aor-- /dev/sdb1(1)
[lv_rimage_2] vg Iwi-aor-- /dev/sdc1(1)
[lv_rmeta_0] vg ewi-aor-- /dev/sda1(0)
[lv_rmeta_1] vg ewi-aor-- /dev/sdb1(0)
[lv_rmeta_2] vg ewi-aor-- /dev/sdc1(0) ** Note that all the images currently are marked as 'I' even though it is
only the last device that has been added that should be marked.
Here is an example of the correct output after this patch is applied:
[root@bp-01 lvm2]# lvs -a -o name,vg_name,attr,copy_percent,devices vg
LV VG Attr Cpy%Sync Devices
lv vg rwi-a-r-- 100.00 lv_rimage_0(0),lv_rimage_1(0)
[lv_rimage_0] vg iwi-aor-- /dev/sda1(1)
[lv_rimage_1] vg iwi-aor-- /dev/sdb1(1)
[lv_rmeta_0] vg ewi-aor-- /dev/sda1(0)
[lv_rmeta_1] vg ewi-aor-- /dev/sdb1(0)
[root@bp-01 lvm2]# lvconvert -m +1 vg/lv; lvs -a -o name,vg_name,attr,copy_percent,devices vg
LV VG Attr Cpy%Sync Devices
lv vg rwi-a-r-- 0.00 lv_rimage_0(0),lv_rimage_1(0),lv_rimage_2(0)
[lv_rimage_0] vg iwi-aor-- /dev/sda1(1)
[lv_rimage_1] vg iwi-aor-- /dev/sdb1(1)
[lv_rimage_2] vg Iwi-aor-- /dev/sdc1(1)
[lv_rmeta_0] vg ewi-aor-- /dev/sda1(0)
[lv_rmeta_1] vg ewi-aor-- /dev/sdb1(0)
[lv_rmeta_2] vg ewi-aor-- /dev/sdc1(0)
** Note only the last image is marked with an 'I'. This is correct and we can
tell that it isn't the whole array that is sync'ing, but just the new
device.
It also works under snapshots...
[root@bp-01 lvm2]# lvs -a -o name,vg_name,attr,copy_percent,devices vg
LV VG Attr Cpy%Sync Devices
lv vg owi-a-r-p 33.47 lv_rimage_0(0),lv_rimage_1(0),lv_rimage_2(0)
[lv_rimage_0] vg iwi-aor-- /dev/sda1(1)
[lv_rimage_1] vg Iwi-aor-p /dev/sdb1(1)
[lv_rimage_2] vg Iwi-aor-- /dev/sdc1(1)
[lv_rmeta_0] vg ewi-aor-- /dev/sda1(0)
[lv_rmeta_1] vg ewi-aor-p /dev/sdb1(0)
[lv_rmeta_2] vg ewi-aor-- /dev/sdc1(0)
snap vg swi-a-s-- /dev/sda1(51201)
fmt1 doesn't have a separate commit function: updates take effect
immediately vg_write is called, so we must update lvmetad at this
point if we're going to go on and ask lvmetad for the VG metadata
again before calling the commit function (though that's probably an
unsupported and pointless thing to do anyway as the client must
already have that data and it cannot have changed because it's locked
and with devs suspended we shouldn't be communicating with lvmetad;
so when that's fixed properly, this fix here can be reverted).
This problem showed up as an internal error when lvremoving an LVM1
snapshot.
> Internal error: LV snap1 (00000000000000000000000000000001) missing from preload metadata
https://bugzilla.redhat.com/891855
If a RAID array is not in-sync, replacing devices should not be allowed
as a general rule. This is because the contents used to populate the
incoming device may be undefined because the devices being read where
not in-sync. The kernel enforces this rule unless overridden by not
allowing the creation of an array that is not in-sync and includes a
devices that needs to be rebuilt.
Since we cannot know the sync state of an LV if it is inactive, we must
also enforce the rule that an array must be active to replace devices.
That leaves us with the following conditions:
1) never allow replacement or repair of devices if the LV is in-active
2) never allow replacement if the LV is not in-sync
3) allow repair if the LV is not in-sync, but warn that contents may
not be recoverable.
In the case where a user is performing the repair on the command line via
'lvconvert --repair', the warning is printed before the user is prompted
if they would like to replace the device(s). If the repair is automated
(i.e. via dmeventd and policy is "allocate"), then the device is replaced
if possible and the warning is printed.
If the lvmcache_info_from_pvid() fails to find valid
info, invoke the lookup by dev, and only in this case
call lvmcache_info_from_pvid() again.
Also check for the result of info and return
error directly, so the NULL is not passed
to lvmcache_get_label().
Commit bf2741376d started to use
lv_is_active() instead of call for lv_info & info.exists so
we cover also cluster activated devices.
For snapshost the conversion was not correct and introduced
regression by blocking creation of snapshot of inactive LV.
Fix it by assigning lv_is_active() directly.
Note: we still have minor issue to fix - to make
lv_is_???? function able to return error states since
lv_info() may fail.
Target tells us its version, and we may allow different set of options
to be supported with different version of driver.
Idea is to provide individual feature flags and later be
able to query for them.
The 'copy_percent' function takes the 'extents_copied' field from each
segment in an LV to create the numerator for the ratio that is to
become the copy_percent. (Otherwise known as the 'sync' percent for
non-pvmove uses, like mirror LVs and RAID LVs.) This function safely
works on RAID - not just mirrors - so it is better to have it in
lv_manip.c rather than mirror.c.
There's a lot of different functions that do a lot of different things
in lv_manip.c, so I placed the function near a function in lv_manip.c
that it was close to in metadata-exported.h. Different placement in the
file or a different name for the function may be useful.
Use log_warn to print non-fatal warning messages.
Use of log_error would confuse checker for testing
whether proper error has been reported for some real error.
A message is printed when the region_size of a RAID LV is adjusted
to allow for large (> ~1TB) LVs. The message wasn't very clear.
Hopefully, this is better.
It would be possible to activate a RAID LV exclusively in a cluster
volume group, but for now we do not allow RAID LVs to exist in a
clustered volume group at all. This has two components:
1) Do not allow RAID LVs to be created in a clustered VG
2) Do not allow changing a VG from single-machine to clustered
if there are RAID LVs present.
MD's bitmaps can handle 2^21 regions at most. The RAID code has always
used a region_size of 1024 sectors. That means the size of a RAID LV was
limited to 1TiB. (The user can adjust the region_size when creating a
RAID LV, which can affect the maximum size.) Thus, creating, extending or
converting to a RAID LV greater than 1TiB would result in a failure to
load the new device-mapper table.
Again, the size of the RAID LV is not limited by how much space is allocated
for the metadata area, but by the limitations of the MD bitmap. Therefore,
we must adjust the 'region_size' to ensure that the number of regions does
not exceed the limit. I've added code to do this when extending a RAID LV
(which covers 'create' and 'extend' operations) and when up-converting -
specifically from linear to RAID1.
We were using daemon_send_simple until now, but it is no longer adequate, since
we need to manipulate requests in a generic way (adding a validity token to each
request), and the tree-based request interface is much more suitable for this.
Don't try to issue discards to a missing PV to avoid segfault.
Prevent lvremove from removing LVs that have any part missing.
https://bugzilla.redhat.com/857554
Failing to clear the LV_NOTSYNCED flag when converting a RAID1 LV to
linear can result in the flag being present after an upconvert - even
if the sync is performed when upconverting.
Mirrors do not allow upconverting if the LV has been created with --nosync.
We will enforce the same rule for RAID1. It isn't hugely critical, since
the portions that have been written will be copied over to the new device
identically from either of the existing images. However, the unwritten
sections may be different, causing the added image to be a hybrid of the
existing images.
Also, we are disallowing the addition of new images to a RAID1 LV that has
not completed the initial sync. This may be different from mirroring, but
that is due to the fact that the 'mirror' segment type "stacks" when adding
a new image and RAID1 does not. RAID1 will rebuild a newly added image
"inline" from the existant images, so they should be in-sync.
We cannot add images to a RAID array while it is not in-sync. The
kernel will simply reject the table, saying:
'rebuild' specified while array is not in-sync
Now we check to ensure the LV is in-sync before attempting image
additions.
It is necessary when creating a RAID LV to clear the new metadata areas.
Failure to do so could result in a prepopulated bitmap that would cause
the new array to skip syncing portions of the array. It is a requirement
that the metadata LVs be activated and cleared in the process of creating.
However in test mode, this requirement should be lifted - no new LVs should
be created or written to.
When printing a message for the user and the lv_segment pointer is available,
use segtype->ops->name() instead of segtype->name. This gives a better
user-readable name for the segment. This is especially true for the
'striped' segment type, which prints "linear" if there is an area_count of
one.
Accept -q as the short form of --quiet.
Suppress non-essential standard output if -q is given twice.
Treat log/silent in lvm.conf as equivalent to -qq.
Review all log_print messages and change some to
log_print_unless_silent.
When silent, the following commands still produce output:
dumpconfig, lvdisplay, lvmdiskscan, lvs, pvck, pvdisplay,
pvs, version, vgcfgrestore -l, vgdisplay, vgs.
[Needs checking.]
Non-essential messages are shifted from log level 4 to log level 5
for syslog and lvm2_log_fn purposes.
This patch adds support for RAID10. It is not the default at this
stage. The user needs to specify '--type raid10' if they would like
RAID10 instead of stacked mirror over stripe.
Adding couple INTERNAL_ERROR reports for unwanted parameters:
Ensure the 'top' metadata node cannot be NULL for lvmetad.
Make obvious vginfo2 cannot be NULL.
Report internal error if handler and vg is undefined.
Check for handle in poll_vg().
Ensure seg is not NULL in dev_manager_transient().
Report missing read_ahead for _lv_read_ahead_single().
Check for report handler in dm_report_object().
Check missing VG in _vgreduce_single().
Respond with "unknown" rather than a NULL pointer if there's an
internal error and the discard value is invalid.
Don't accept 'no_passdown' or 'no-passdown' variants in the LVM
metadata: this is written by the program so should only ever contain
"nopassdown" and should be validated strictly against that.
Commit 8767435ef8 allowed RAID 4/5/6
LV to be extended properly, but introduced a regression in device
replacement - a critical component of fault tolerance.
When only 1 or 2 drives are being replaced, the 'area_count' needed
can be equal to the parity_count. The 'area_multiple' for RAID 4/5/6
was computed as 'area_count - parity_devs', which could result in
'area_multiple' being 0. This would ultimately lead to a division by
zero error. Therefore, in calc_area_multiple, it is important to take
into account the number of areas that are being requested - just as
we already do in _alloc_init.
Add arg support for discard.
Add discard ignore, nopassdown, passdown (=default) support.
Flags could be set per pool.
lvcreate [--discard {ignore|no_passdown|passdown}] vg/thinlv
Reducing a RAID 4/5/6 LV or extending it with a different number of
stripes is still not implemented. This patch covers the "simple" case
where the LV is extended with the same number of stripes as the orginal.
If _alloc_parallel_area for raid devices chooses an area already used
up, it doesn't notice that it has no space left in it and leaves
later code trying to place a zero-length area into the LV.
https://bugzilla.redhat.com/832596
One can use "lvcreate --aay" to have the newly created volume
activated or not activated based on the activation/auto_activation_volume_list
this way.
Note: -Z/--zero is not compatible with -aay, zeroing is not used in this case!
When using lvcreate -aay, a default warning message is also issued that zeroing
is not done.
Define an 'activation_handler' that gets called automatically on
PV appearance/disappearance while processing the lvmetad_pv_found
and lvmetad_pv_gone functions that are supposed to update the
lvmetad state based on PV availability state. For now, the actual
support is for PV appearance only, leaving room for PV disappearance
support as well (which is a more complex problem to solve as this
needs to count with possible device stack).
Add a new activation change mode - CHANGE_AAY exposed as
'--activate ay/-aay' argument ('activate automatically').
Factor out the vgchange activation functionality for use in other
tools (like pvscan...).
We're refererring to 'activation' all over the code and we're talking
about 'LVs being activated' all the time so let's use 'activation/activate'
everywhere for clarity and consistency (still providing the old
'available' keyword as a synonym for backward compatibility with
existing environments).
Update release_lv_segment_area not to discard any PV extents,
as it also gets used when moving extents between LVs.
Instead, call a new function release_and_discard_lv_segment_area() in
the two places where data should be discarded - lv_reduce() and
remove_mirrors_from_segments().
When mirrors are up-converted, a transient mirror layer is put in so that
only the new devices are sync'ed. That transient layer must carry the tags
of the original mirror LV, otherwise it will fail to activate when activation
is regulated by lvm.conf:activation/volume_list. The conversion would then
fail.
The fix is to do exactly the same thing that is being done for linear ->
mirror converting (lib/metadata/mirror.c:_init_mirror_log()). We copy the
tags temporarily for the new LV and remove them after the activation.
Snapshots of RAID logical volumes are allowed (including "raid1"). However,
snapshots of "mirror" logical volumes has been disallowed due to unsolvable
issues inherent to the design. The fact that mirroring (dm-raid1.c) must
stop all I/O as the result of a failure and wait for userspace intervention
can lead to a circular dependency if userspace is simultaneously waiting for
snapshots (on mirrors) to make an I/O update before proceeding.
Various snapshot on mirror tests have been removed as a result.
If two devices in an array failed, it was previously impossible to replace
just one of them. This patch allows for the replacement of some, but perhaps
not all, failed devices.
The logic for resuming the original and newly split LVs was not properly
done to handle situations where anything but the last device in the array
was split. It did not take into account the possible name collisions that
might occur when the original LV undergoes the shifting and renaming of its
sub-LVs.
In this case we should allow to use local mirror, check for cmirror
should apply only for lvconvert/lvcreate.
Introduced in 2.02.86 by removing !(lv->status & ACTIVATE_EXCL).
(Partially workaround, it is minimalistic patch for now.)
Code adds better support for monitoring of thin pool devices.
update_pool_lv uses DMEVENTD_MONITOR_IGNORE to not manipulate with monitoring.
vgchange & lvchange are checking real thin pool device for existance
as we are using _tpool real device and visible LV pool device might not
be even active (_tpool is activated implicitely for any thin volume).
monitor_dev_for_events is another _lv_postorder like code it might be worth
to think about reusing it here - for now update the code to properly
monitory thin volume deps.
For unmonitoring add extra code to check the usage of thin pool - in case it's in use
unmonitoring of thin volume is skipped.
When down-converting a RAID1 device, it is the last device that is extracted
and removed when the user does not specify a particular device. However,
when a device is specified (and it is not the last), the device is removed and
the remaining sub-LVs are "shifted down" to fill the hole. This cause problems
when resuming the LV because if the shifted devices were resumed (and thus
renamed) before the sub-LV being extracted, there would be a name conflict.
The solution is to resume the extracted sub-LVs first so that they can be
properly renamed preventing a possible conflict.
This addresses bug 801967.
Add 3rd daemon return state "unknown" for lookups that are carried out
successfully but don't find the item requested.
Avoid issuing error messages when it's expected that a device that's
being looked up in lvmetad might not be there.
If the thin pool has disabled zeroing (created with -Zn), we at least
clear initial 4KiB of such thin volume (provisions 1st block).
If lvcreate is executed with '-an' command will abort (same way like we for
normal LV - however for normal LV option -Zn may skip clearing completely,
for thin volumes this option is not supported (applies only for pools).
Adding at least stack traces with some FIXMEs for cases,
where we might want to do something cleaver - maybe fail command
or give user hints something is not going well ?
For remote_backup is stack probably 'good' enough for now.
The code fail to account for the case where we just need a single device
in a RAID 4/5/6 array. There is no good way to tell the allocation functions
that we don't need parity devices when we are allocating just a single device.
So, I've used a bit of a hack. If we are allocating an area_count that is <=
the parity count, then we can assume we are simply allocating a replacement
device (i.e. no need to include parity devices in the calculations). This
should make sense in most cases. If we need to allocate replacement devices
due to failure (or moving), we will never allocate more than the parity count;
or we would cause the array to become unusable. If we are creating a new device,
we should always create more stripes than parity devices.
Read lvm.conf setting for monitoring for each command. So we should not
activate monitoring if the default compilation is set to monitor during
lvconvert commnads.
Patch also removes check for clustered VG and allows to disable monitoring
for clustered VG with the assumption, the problem with monitoring and dmeventd
flag passing for INGNORE is already fixed.
Move commod code to destroy orphan VG into free_orphan_vg() function.
Use orphan vgmem for creation of PV lists.
Remove some free_pv_fid() calls (FIXME: check all of them)
FIXME: Check whether we could merge release_vg back again for all VGs.
Before removing thin pool LV always make sure, stacked message
for previous run are cleared - but allow to remove any
device that should have been created
(i.e. creation of snapshot failed - so the message for snapshot creation
may be replaced with delete message within unfinished transaction).
Also commit messages after lv remove - so free space is released in pool.
Extend the usage of origin_only flag to allow resume of thin pool LV
(when it's active) to pass only the messages.
origin_only flag will skip detection of already resumed tree for thin_pool,
so we do not need to suspend the tree and we just send messages.
Add pool_has_message and use it in attach_pool_message.
Also update header to make more obvious which segment type is
expected as parameter.
Rename 'read_only' to 'no_update' (no auto update transaction_id)
to better fit how it's used.
Fix problem when there was only one stacked message replaced with delete
message that caused unwanted transaction_id increase.
Failure to do so results in "Performing unsafe table load while X device(s) are
known to be suspended" errors. While fixing the problem in this way works and
is consistent with the way the mirror segment type does it, it would be nice
to find a solution that uses the generic suspend/resume calls.
Also included in this check-in are additions to the test suite that perform
conversions on RAID LVs under a snapshot. These tests are disabled for the
time being due to a kernel bug that is yet to be tracked down.
Since striped name function knows when to report 'linear' instead of
'stripe' type name - drop it from this place.
This fixes problem when reporting segtype e.g. for thin-pool which
is also using area_count=1 to store thin data device reference.
It also returns properly strduped memory instead of badly casted const char*.
Since snapshot needs to suspend origin - it might lead to pool userspace
deadlock (as the pool will wait for new space in case it would be overfilled,
but dmeventd would not be able to resize it, as the lvcreate operation would
have kept the VG lock.)
To minimize the risk of such scenario - we prevent to create new snapshot
in case we are over the threshold - but beware, there is still small timewindow,
so keep threshold at some reasonable level!
New field Data% is able to display info about
thin_pool, thin, snapshot and has generic meaning here.
Simple Time/Host field are here to display host and time creation.
Basic support to keep info when the LV was created.
Host and time is stored into LV mda section.
FIXME: Current version doesn't support configurable string via lvm.conf
and used fixed version strftime "%Y-%m-%d %T %z".
Also, don't allow a splitmirror operation on a RAID LV that is already tracking
a split, unless the operation is to stop the tracking and complete the split.
Example:
~> lvconvert --splitmirrors 1 --trackchanges vg/lv /dev/sdc1
# Now tracking changes - image can be merged back or split-off for good
~> lvconvert --splitmirrors 1 -n new_name vg/lv /dev/sdc1
# ^ Completes split ^
If a split is performed on a RAID that is tracking an already split image and
PVs are provided, we must ensure that
1) the already split LV is represented in the PVs
2) we are careful to split only the tracked image
RAID is not like traditional LVM mirroring. LVM mirroring required failed
devices to be removed or the logical volume would simply hang. RAID arrays can
keep on running with failed devices. In fact, for RAID types other than RAID1,
removing a device would mean substituting an error target or converting to a
lower level RAID (e.g. RAID6 -> RAID5, or RAID4/5 to RAID0). Therefore, rather
than removing a failed device unconditionally and potentially allocating a
replacement, RAID allows the user to "replace" a device with a new one. This
approach is a 1-step solution vs the current 2-step solution.
example> lvconvert --replace <dev_to_remove> vg/lv [possible_replacement_PVs]
'--replace' can be specified more than once.
example> lvconvert --replace /dev/sdb1 --replace /dev/sdc1 vg/lv
Use static buffer instead of stack allocated buffer.
This reduces stack size usage of lvm tool and the
change is very simple.
Since the whole library is not thread safe - it should not
add any new problems - and if there will be some conversion
it's easy to convert this to use some preallocated buffer.
For write we do not need to hold memory locked.
This relaxes many conditions and avoid problems when allocating
a lot of memory for writting metadata buffers.
(In case of huge MDA size this would lead to mismatch between
locked and unlocked memory region size).
Add also internal check we are not writing in critical section.
Removal of an inactive origin removes also all related snapshots.
When we now support 'old' external snapshots with thin volumes,
removal of pool will not only drop all thin volumes, but as
a consequence also all snapshots - which might be seen a bit
unexpected for the user - so add a query to confirm such action.
lvremove -f will skip the prompt.
Update region_size only for mirror and raid targets.
This fixes warning messages when vg is using small
extent size like 1KiB and no mirror/raid is created,
but the user still got the message:
$> vgcreate -s 1K vg <pvs>
$> lvcreate -L10K vg
Using reduced mirror region size of 4 sectors
If the extent_size is smaller then the chunk_size we may try
to find better aligment (wasting less space).
i.e. using 4KB extent_size and 64KB chunk size will
lead to creation of 64KB aligned thin volume.
Support allocation of metadata from the same PV, if the VG
is build only from one PV.
As thinp is not mirror - we do not require 2 PVs
for basic thin usage as user is losing only perfomance.
Replace detach_pool_messages with update_pool_lv.
Move creation code from to 'if' condition into 1.
Ensure creation has finished all previous message operations.
All thins are created with the next activation and VG is updated
without messages. Only some basic commands works.
(i.e. lvcreate -an -V10 -T mvg/pool)
There can be some combination to confuse this system.
This functionality for snapshots is going to be interesting.
If something fails during creation of thin LV remove such LV
and deactivate in case it's been already tried to activate
(i.e. thin kernel driver fails for some reason.)
To ensure we properly handle LV cluster locking - explicitely do
not allow to change the availability of the thin pool that is in use
for some thin LV.
As soon as the thin volume is created the only way to activate pool
is via implicit dependency.
Ignore thinpool open count for lv/vgchange operations.
Before adding a new virtual segment to LV, check first whether
the last segment isn't already of the same type. In this case
extend last segment instead of creating the new one.
Thin volumes should have always only 1 virtual segment, but it
helps also to virtual snapshot or error segtype..
Git commit ID 0864378250 was meant to disallow
'mirrored' logs for cluster mirrors. However, when add_mirror_log is used
to create the log (as is now the case when using 'lvcreate' or converting only
the log) the check is bypassed.
This patch adds the check to add_mirror_log.
pvck prints 'extra' character from the label since there is no '\0'
after the struct label entry and just uint64_t follows directly.
So avoid it by limiting 8 chars to be printed.
https://www.redhat.com/archives/lvm-devel/2011-January/msg00109.html
Signed-off-by: Paul Bolle <pebolle tiscali nl>
Since thin is not able to use _lv_insert_empty_sublvs,
remove its appearence from this function.
Start to use extend_pool() function for desired functionality
and modify lv_extend() for this.
Code in _lv_insert_empty_sublvs was not able to provide proper
initialization order for thin pool LV.
New function extend_pool() first adds metadata segment to pool LV which
is still visible. Such LV is activate and cleared.
Then new meta LV is created and metadata segments are moved there.
Now the preallocated pool data segment is attached to the pool LV
and layer _tpool is created. Finaly segment is marked as thin_pool.
This function could be useful for other _manip source files.
Use dm_list manipulation function for provided functionality,
which make the code more readable and avoid touching list
internal details here.
Couple FIXMEs put into the code for parts of the code which may be
improved later, since we might be able to add 'lazy' device creation later.
For now require exclusive activation.
lvm part of messaging.
Each message is now stored it's own thin pool section:
message1 {
create = lv
}
Messages are queued to thin pool dm target when this target
is going to be resumed or used through some dependency.
Currently 'delete' message are purely queued and processed
with next thin pool resume operation (i.e. create_thin).
WARNING - thin provisioning support is developmental code.
Properly detect if the filters were refreshed properly.
(May needs few more fixes ??)
Filter refresh may fail because it may be out of free file descriptors
when clvmd gets overloaded.
Example:
~> lvconvert --type raid1 vg/mirror_lv
Steps to convert "mirror" to "raid1"
1) Allocate a RAID metadata LV for each mirror image from the same PVs
on which they are located.
2) Clear the metadata LVs. This involves writing LVM metadata, so we don't
change any aspects of the mirror LV before this so that the user can easily
remove LVs from the failed convert attempt while retaining the original
mirror.
3) Remove the mirror log, if it exists.
4) Add metadata LVs to mirror LV
5) Rename mirror sub-lvs (s/mimage/rimage/)
6) Change flags and segtype from mirror to raid1
Example:
~> lvconvert --type raid1 -m 1 vg/lv
The following steps are performed to convert linear to RAID1:
1) Allocate a metadata device from the same PV as the linear device
to provide the metadata/data LV pair required for all RAID components.
2) Allocate the required number of metadata/data LV pairs for the
remaining additional images.
3) Clear the metadata LVs. This performs a LVM metadata update.
4) Create the top-level RAID LV and add the component devices.
We want to make any failure easy to unwind. This is why we don't create the
top-level LV and add the components until the last step. Should anything
happen before that, the user could simply remove the unnecessary images. Also,
we want to ensure that the metadata LVs are cleared before forming the array to
prevent stale information from polluting the new array.
A new macro 'seg_is_linear' was added to allow us to distinguish linear LVs
from striped LVs.
This patch allows a mirror to be extended without an initial resync of the
extended portion. It compliments the existing '--nosync' option to lvcreate.
This action can be done implicitly if the mirror was created with the '--nosync'
option, or explicitly if the '--nosync' option is used when extending the device.
Here are the operational criteria:
1) A mirror created with '--nosync' should extend with 'nosync' implicitly
[EXAMPLE]# lvs vg; lvextend -L +5G vg/lv ; lvs vg
LV VG Attr LSize Pool Origin Snap% Move Log Copy% Convert
lv vg Mwi-a-m- 5.00g lv_mlog 100.00
Extending 2 mirror images.
Extending logical volume lv to 10.00 GiB
Logical volume lv successfully resized
LV VG Attr LSize Pool Origin Snap% Move Log Copy% Convert
lv vg Mwi-a-m- 10.00g lv_mlog 100.00
2) The 'M' attribute ('M' signifies a mirror created with '--nosync', while 'm'
signifies a mirror created w/o '--nosync') must be preserved when extending a
mirror created with '--nosync'. See #1 for example of 'M' attribute.
3) A mirror created without '--nosync' should extend with 'nosync' only when
'--nosync' is explicitly used when extending.
[EXAMPLE]# lvs vg; lvextend -L +5G vg/lv; lvs vg
LV VG Attr LSize Pool Origin Snap% Move Log Copy% Convert
lv vg mwi-a-m- 20.00m lv_mlog 100.00
Extending 2 mirror images.
Extending logical volume lv to 5.02 GiB
Logical volume lv successfully resized
LV VG Attr LSize Pool Origin Snap% Move Log Copy% Convert
lv vg mwi-a-m- 5.02g lv_mlog 0.39
vs.
[EXAMPLE]# lvs vg; lvextend -L +5G vg/lv --nosync; lvs vg
LV VG Attr LSize Pool Origin Snap% Move Log Copy% Convert
lv vg mwi-a-m- 20.00m lv_mlog 100.00
Extending 2 mirror images.
Extending logical volume lv to 5.02 GiB
Logical volume lv successfully resized
LV VG Attr LSize Pool Origin Snap% Move Log Copy% Convert
lv vg Mwi-a-m- 5.02g lv_mlog 100.00
4) The 'm' attribute must change to 'M' when extending a mirror created without
'--nosync' is extended with the '--nosync' option. (See #3 examples above.)
5) An inactive mirror's sync percent cannot be determined definitively, so it
must not be allowed to skip resync. Instead, the extend should ask the user if
they want to extend while performing a resync.
[EXAMPLE]# lvchange -an vg/lv
[EXAMPLE]# lvextend -L +5G vg/lv
Extending 2 mirror images.
Extending logical volume lv to 10.00 GiB
vg/lv is not active. Unable to get sync percent.
Do full resync of extended portion of vg/lv? [y/n]: y
Logical volume lv successfully resized
6) A mirror that is performing recovery (as opposed to an initial sync) - like
after a failure - is not allowed to extend with either an implicit or
explicit nosync option. [You can simulate this with a 'corelog' mirror because
when it is reactivated, it must be recovered every time.]
[EXAMPLE]# lvcreate -m1 -L 5G -n lv vg --nosync --corelog
WARNING: New mirror won't be synchronised. Don't read what you didn't write!
Logical volume "lv" created
[EXAMPLE]# lvs vg
LV VG Attr LSize Pool Origin Snap% Move Log Copy% Convert
lv vg Mwi-a-m- 5.00g 100.00
[EXAMPLE]# lvchange -an vg/lv; lvchange -ay vg/lv; lvs vg
LV VG Attr LSize Pool Origin Snap% Move Log Copy% Convert
lv vg Mwi-a-m- 5.00g 0.08
[EXAMPLE]# lvextend -L +5G vg/lv
Extending 2 mirror images.
Extending logical volume lv to 10.00 GiB
vg/lv cannot be extended while it is recovering.
7) If 'no' is selected in #5 or if the condition in #6 is hit, it should not
result in the mirror being resized or the 'm/M' attribute being changed.
NOTE: A mirror created with '--nosync' behaves differently than one created
without it when performing an extension. The former cannot be extended when
the mirror is recovering (unless in-active), while the latter can. This is
a reasonable thing to do since recovery of a mirror doesn't take long (at
least in the case of an on-disk log) and it would cause far more time in
degraded mode if the extension w/o '--nosync' was allowed. It might be
reasonable to add the ability to force the operation in the future. This
should /not/ force a nosync extension, but rather force a sync'ed extension.
IOW, the user would be saying, "Yes, yes... I know recovery won't take long
and that I'll be adding significantly to the time spent in degraded mode, but
I need the extra space right now!".
This patch also does some clean-up of the splitmirrors code.
I've attempted to clean-up the splitmirrors code to make it easier to
understand with fewer operations. I've tried to reduce the number of
metadata operations without compromising the intermediate stages which
are necessary for easy clean-up in the even of failure.
These changes now correctly handle cluster situations - including exclusive
cluster mirrors. Whereas before, a splitmirror operation would result in
remote nodes having LVM commands report the newly split LV with a proper
name while DM commands would report the old (pre-split) names of the device.
IOW, there was a kernel/userspace mismatch.
The original commit comments can be located via this git commit ID:
7d8e615c0b
There were three possible solutions to the original problem proposed in the
initial check-in. The one chosen was as follows:
2) Do like _remove_mirror_images does and suspend the original, then suspend
the sub-lv (the error target), then resume the sub-lv, and finally resume the
original LV. This seems like extra pointless operations to me, but it doesn't
produce the error message (although, I'm not sure why) and it allows us to
leave the visible flag in place.
Turns out, the cluster also views the extra suspend/resume operations as
pointless too and ignores them. So, this solution doesn't work in a cluster.
Further, I've noticed that in addition to the remote cluster nodes still getting
I/O errors from scanning the error target, they also have a different LVM and
DM views of the same LV. IOW, while the LVM level (gotten from the LVM metadata)
sees the correct name for the newly split LV, device-mapper still maintains the
old names.
Because the original fix failed to completely fix the problem (or work-around it)
and because a better solution must be found to address the additional cluster
issue of device renaming, I am reverting the above mentioned commit.
Make limits for thin data_block_size and device_id part of public API.
FIXME: read them possible from some kernel header file in the future ?
But we may need to support different values for different versions ?
Before, we used to display "Can't remove open logical volume" which was
generic. There 3 possibilities of how a device could be opened:
- used by another device
- having a filesystem on that device which is mounted
- opened directly by an application
With the help of sysfs info, we can distinguish the first two situations.
The third one will be subject to "remove retry" logic - if it's opened
quickly (e.g. a parallel scan from within a udev rule run), this will
finish quickly and we can remove it once it has finished. If it's a
legitimate application that keeps the device opened, we'll do our best
to remove the device, but we will fail finally after a few retries.
seg->areas and seg->meta_areas. We also need to copy the memory from the
old arrays to the newly allocated arrays. The amount of memory to copy was
determined by seg->area_count. However, seg->area_count was being set to the
higher value after copying the 'seg->areas' information, but before copying
the 'seg->meta_areas' information. This means we were copying more memory
than necessary for 'seg->meta_areas' - something that could lead to a segfault.
Compiler says variable may be used uninitialized. It can't be, but we
initialize the variable to NULL anyway. Also, remove the double initialization
of another variable.
This bug showed up when trying to add a log to a mirror whose images are on
multiple devices. This is an intra-release regression and no WHATS_NEW
entry will be added. The error was introduce in the following commit:
2d8a2f35c7
The solution is to recognise in _alloc_init that if there are no mirrors
or stripes specified, then 'new_extents' should be zero.
to settle udev before calling deactivate_lv.
This is an intra-release regression (no WHATS_NEW entry required). It is
part of the fix for the current WHATS_NEW entry:
Work around resume_lv causing error LV scanning during splitmirror operation.
When user wants to remove thin pool - check if there are no thin volumes using it.
If so - query before removal (or -ff for no question) and remove them first.
When LV is unlinked, we want to catch problem in vg_validate,
that LV has changed.
i.e. catch LV has been removed and is no long thin_pool while still
being referenced by some thin volume.
Revert John patch, which fixed only 1 place where ~LVM_WRITE was in use and
convert ommited LVM_READ/WRITE flags to 64bit constants as well.
(Since both 'status' flags for LV and VG are 64bit.)
Changing lv_mirror_count to only count the AREA_LVs made the function
stop working for PVMOVE mirrors. A conditional has been added to fix
that problem. Additionally, when counting the images in a mirror stack,
we don't need to subtract 1 from the count we get back from the
lv_mirror_count call on the temporary mirror layer. (This is because we
are no falsely counting the top layer of the temporary mirror.)
lv_mirror_count was not able to handle mirrors of stripes properly. When a
failed device is removed, the MIRRORED status flag is removed from the LV
conditionally based on the results of lv_mirror_count. However, lv_mirror_count
trusted the MIRRORED flag - thinking any such LV must be mirrored. It would
happily assign first_seg(lv)->area_count as the number of mirrors, but when
a mirrored striped LV was reduced to a simple striped LV area_count would be
the number of /stripes/ not the number of /mirrors/. A result higher than 1
would be returned from lv_mirror_count, the MIRRORED flag would not be cleared,
and the LV would fail to be up-converted properly in lvconvert_mirrors_aux
because of it.
The operation of deactivating the residual error target LV after removing a
mirror layer can cause a "device in-use" conflict with udev. Giving udev a
poke before calling deactivate_lv eliminates the conflict. The stick used
to poke udev is 'sync_local_dev_names'.
Kernel requires a mirror to be at least 1 region large. So,
if our mirror log is itself a mirror, it must be at least
1 region large. This restriction may not be necessary for
non-mirrored logs, but we apply the rule anyway.
(The other option is to make the region size of the log
mirror smaller than the mirror it is acting as a log for,
but that really complicates things. It's much easier to
keep the region_size the same for both.)
WHATS_NEW entry:
Fix log size calculation when only a log is being added to a mirror.
The original fix pass the mirror LV to allocate_extents (rather than
passing NULL) so that _alloc_init could correctly determine the necessary
size of the mirror log. In the previous check-in, I noted:
In order to get a decent value computed, we need to pass in the 'lv' argument
to allocate_extents. This would normally imply a desire for cling/contiguous
allocation to the given LV, but since we are not allocating any parallel
extents and only log extents, it works fine.
However, passing in the LV did have unintended consequences on the placement of
the log. The better solution is to pass in the number of extext that are in
the mirror LV instead of the LV itself. This will not cause the allocator to
reserve that number of extents, because 'stripes' and 'mirrors' are specified
as 0. Thus, 'extents' is used to calculate the size of the log, but won't
affect how much is allocated.
LVM_WRITE is a 32-bit flag. Now that RAID[_IMAGE|_META] are 64-bit,
and'ing a RAID LV's status against LVM_WRITE can reset the higher order
flags.
A similar thing will affect thinp flags if not careful.
_alloc_init calculates the number of necessary log extents via
'mirror_log_extents'. 'mirror_log_extents' takes 3 arguments: region_size,
pe_size, and size of the mirror LV. Unfortunately, _alloc_init is guessing at
the mirror size by using 'ah->new_extents / ah->area_multiple' - the number of
extents that the mirror images have. However, this is /always/ wrong when
allocating the log separately. Further, the log is always allocated separately
unless we are up-converting the mirror at the same time. It was by luck alone
that a default value of '1' reflects what we want in most cases.
In order to get a decent value computed, we need to pass in the 'lv' argument
to allocate_extents. This would normally imply a desire for cling/contiguous
allocation to the given LV, but since we are not allocating any parallel
extents and only log extents, it works fine.
When an image is split from a 2-way mirror, the original mirror is converted to
a linear device. To do this, the top "layer" must be removed. The segments
are transferred from the sub-lv to the top-level LV and the link is severed.
The former sub-lv - having its segments transferred - now contains a temporary
error target.
When the original LV is resumed, the old sub-lv that now contains an error
segment is activated and scanned. This is what causes the I/O error messages.
There are three ways to fix this problem:
1) Do not set the sub-lv which contains the error target as "visible" before
suspending the original LV. This way, when the original is resumed, the sub-lv
device node is not created and it is not scanned - avoiding the error messages.
The problem with this approach is that if the machine crashes after the
resume, it leaves the *hidden* LV in place and the user has a more difficult
time noticing that it needs to be cleaned up. Thus, this type of processing is
frowned upon.
2) Do like _remove_mirror_images does and suspend the original, then suspend
the sub-lv (the error target), then resume the sub-lv, and finally resume the
original LV. This seems like extra pointless operations to me, but it does not
produce the error message (although, I'm not sure why) and it allows us to
leave the visible flag in place.
3) Flag the sub-lv (error target) with a "do not scan" flag. This seems like
the cleanest approach, but I have been unable to find the method for doing
this. LVs get tagged in such a way by _get_udev_flags, but in this case the
resume of the original LV also resumes the error target LV without running it
through _get_udev_flags (likely because they are no longer linked). Could
there be something wrong in resume_lv?
Option #2 was chosen to fix this bug, but it seems like more of a workaround
for now.
A gentle reminder that anyone relying on the output of reporting commands
like lvs in scripts must use -o to guarantee they get the fields they expect.
The default sequence of fields can change from release to release.
Equally, the 'attr' fields can have new values introduced and/or characters
appended to them.
There was a bad sequence:
*) Make changes to LV layout to split images (e.g. 4-way -> 2-way/2-way)
1) vg_write, suspend_lv(original_mirror), vg_commit
2) activate_lv(newly_split_lv)
3) resume_lv(original_mirror)
Step #2 is not allowed. However, without it, the resume of the original
mirror will also resume its former sub-LVs - making it impossible to
activate the newly split LV due to the changes in layering, pointers, and
names that had already been made. Additionally, the resume or the original
brings the sub-lv's online with names that differ from the metadata on disk -
also a no-no. Thus, the split must be done in stages such that the active LVs
always reflect what is in the committed LVM metadata.
First, alter the original mirror by releasing the images. The images are made
visible and independent as an intermediate stage. (This way, we can have
consistency between LVM metadata and active LVs.) The second stage collects
the recently split LVs, deactivates them, forms them into a mirror if necessary,
and then activates them. It is a bit of a circuitous method, but it is the only
way to split a mirror from a mirror and obey these general rules:
1) Never [de]activate sub-lvs when the top-level LV is suspended
2) Avoid having active LVs that differ from the description in the LVM metadata
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
leaving behind the LVM-specific parts of the code (convenience wrappers that
handle `struct device` and `struct cmd_context`, basically). A number of
functions have been renamed (in addition to getting a dm_ prefix) -- namely,
all of the config interface now has a dm_config_ prefix.
This patch adds the ability to upconvert a raid1 array - say from 2-way to
3-way. It does not yet support upconverting linear to n-way.
The 'raid' device-mapper target allows for individual components (images) of
an array to be specified for rebuild. This mechanism is used when adding
new images to the array so that the new images can be resync'ed while the
rest of the images in the array can remain 'in-sync'. (There is no
mirror-on-mirror layering required.)
~> lvconvert --splitmirrors 1 --trackchanges vg/lv
The '--trackchanges' option allows a user the ability to use an image of
a RAID1 array for the purposes of temporary read-only access. The image
can be merged back into the array at a later time and only the blocks that
have changed in the array since the split will be resync'ed. This
operation can be thought of as a partial split. The image is never completely
extracted from the array, in that the array reserves the position the device
occupied and tracks the differences between the array and the split image via
a bitmap. The image itself is rendered read-only and the name (<LV>_rimage_*)
cannot be changed. The user can complete the split (permanently splitting the
image from the array) by re-issuing the 'lvconvert' command without the
'--trackchanges' argument and specifying the '--name' argument.
~> lvconvert --splitmirrors 1 --name my_split vg/lv
Merging the tracked image back into the array is done with the '--merge'
option (included in a follow-on patch).
~> lvconvert --merge vg/lv_rimage_<n>
The internal mechanics of this are relatively simple. The 'raid' device-
mapper target allows for the specification of an empty slot in an array
via '- -'. This is what will be used if a partial activation of an array
is ever required. (It would also be possible to use 'error' targets in
place of the '- -'.) If a RAID image is found to be both read-only and
visible, then it is considered separate from the array and '- -' is used
to hold it's position in the array. So, all that needs to be done to
temporarily split an image from the array /and/ cause the kernel target's
bitmap to track (aka "mark") changes made is to make the specified image
visible and read-only. To merge the device back into the array, the image
needs to be returned to the read/write state of the top-level LV and made
invisible.
Users already have the ability to split an image from an LV of "mirror"
segtype. This patch extends that ability to LVs of "raid1" segtype.
This patch only allows a single image to be split off, however. (The
"mirror" segtype allows an arbitrary number of images to be split off.
e.g. 4-way => 3-way/linear, 2-way/2-way, linear,3-way)
of top-level LV.
We can't activate sub-lv's that are being removed from a RAID1 LV while it
is suspended. However, this is what was being used to have them show-up
so we could remove them. 'sync_local_dev_names' is a sufficient and
proper replacement and can be done after the top-level LV is resumed.
1) add new function 'raid_remove_top_layer' which will be useful
to other conversion functions later (also cleans up code)
2) Add error messages if raid_[extract|add]_images fails
3) Add function prototypes to prevent compiler warnings when
compiling with '--with-raid=shared'
Fix a couple more issues that kabi found.
- Add some error messages in failure cases
- s/malloc/zalloc/
- use vg->vgmem for lv names instead of vg->cmd->mem
Use debug pool locking functionality. So the command could check,
whether the memory in the pool has not been modified.
For lv_postoder() instead of unlocking and locking for every changed
struct status member do it once when entering and leaving function.
(mprotect would trap each such memory access).
Currently lv_postoder() does not modify other part of vg structure
then status flags of each LV with flags that are reverted back to
its original state after function exit.
Extend vginfo cache with cached VG structure. So if the same metadata
are use, skip mda decoding in the case, the same data are in use.
This helps for operations like activation of all LVs in one VG,
where same data were decoded giving the same output result.
Patch adds 1-to-1 connection between volume_group and lvmcache_vginfo.
Move the free_vg() to vg.c and replace free_vg with release_vg
and make the _free_vg internal.
Patch is needed for sharing VG in vginfo cache so the release_vg function name
is a better fit here.
As this flag could not have been set by the current code - removing it.
Note: because of the wrong code logic this call:
lvmcache_update_vg(correct_vg, correct_vg->status & PRECOMMITTED &
(inconsistent ? INCONSISTENT_VG : 0));
had always passed '0' - now after flag removal it's passing
PRECOMMITTED flag in - this present functinal change in this patch.
To match the original functionality - 0 had to be always passed.
More testing is needed here.
Compiler complaining that meta_lv could be used uninitialized. (Not true
because it is protected by 'clear_metadata'.) I switched to using 'lv->vg',
as it makes no difference to vg_[write|commit].
Last usage was removed in Petr's commit related to VG mda repair fix
where relaxed check starts to ignore inconsistencies coming from
PVs that are marked MISSING - thus removing unused variable.
Implementation described in doc/lvm2-raid.txt.
Basic support includes:
- ability to create RAID 1/4/5/6 arrays
- ability to delete RAID arrays
- ability to display RAID arrays
Notable missing features (not included in this patch):
- ability to clean-up/repair failures
- ability to convert RAID segment types
- ability to monitor RAID segment types
teardown sequence. (Previously the snapshot was deactivated while its
origin was active and before its removal was committed to disk, so
restarting after a crash at the point would leave corruption.)
When an LVM mirror is up-converted (an additional image added), it creates
a temporary mirror stack. The lower-level mirror in the stack that is
created was not being activated exclusively - violating the exclusive nature
of the original mirror. We now check for exclusive activation of a mirror
before converting it, and if found, we ensure that the temporary mirror
is also exclusively activated.
Mirrors used to be created by first creating a linear device and then adding
the other images plus the log. Now mirrors are created by creating all the
images in one go and then adding the log separately. The new way ran into
the condition that cluster mirrors cannot change the log type (in the case
of creation, from core -> disk) while the mirror is not active. (It isn't
active because it is in the process of being created.) The reason this
condition is in place is because a remote node may have the mirror active, and
we don't want to alter the log underneath it.
What we really needed was a way of checking if the mirror was active remotely
but not locally, and in that case do not allow a change of the log. I've added
this check, and cluster mirrors can now be created again.
It's useful to keep the partial flag cached - so just move the call
for vg_mark_partil_lvs() into import_vg_from_config_tree() so it gets
evaluated before it goes through the lvmcache.
This patch should not present any functional change.
Note: It is rather temporal solution - proper place is probably inside the
'read' call back - but needs some more discussion.
For now using this minor hack.
As the ACTIVATE_EXCL could be set only in clvmd code - there is no
use for this test in lv_add_mirrors() function only called from
tools context.
FIXME: Add cluster test case for this.
