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Commit Graph

16 Commits

Author SHA1 Message Date
David Teigland
63b469c160 device_id: fix hints with device ids
Fix some interactions between device IDs and hints.  Hints
may limit the scanned devices which should not always trigger
a search for the PVs that were intentionally not scanned.
Hints should also be invalidated if they contain a device
that's become excluded by an internal filter such as the
device_id filter.
2023-10-10 11:47:29 -05:00
David Teigland
1901a47df1 device_id: fix conditions for device_ids_refresh
Fix commit 847f1dd99c
"device_id: rewrite validation of devname entries"

which began calling device_ids_refresh() in cases where it
was unnecessary, leading to extra PV searches and warnings.
Specifically, a command like "lvs <vg>" would use the hints
file to scan only devices for the named VG.  This means that
scanning other PVs would be skipped, and device IDs of those
PVs could not be validated because there are no PVID values
to verify.  This missing info would cause messages about
the missing info, and would cause device_ids_refresh to
search for the PVs that had been intentionally skipped.
2023-10-05 15:33:55 -05:00
David Teigland
88aa285a79 devices: refresh device ids if the system changes
If the system changes, locate PVs that appear on different devices,
and update the device IDs in the devices file.  A system change is
detected by saving the DMI product_uuid or hostname in the devices
file, and comparing it to the current system value.  If a root PV
is restored or copied to a new system with different devices, then
the product_uuid or hostname should change, and trigger lvm to
locate PVIDs from system.devices on new devices.
2023-09-27 15:22:11 -05:00
David Teigland
761b922178 device_id: handle duplicate serial numbers
Handle multiple devices using the same serial number as
their device id.  After matching devices to devices file
entries, if there is a discrepency between the ondisk PVID
and the devices file PVID, then rematch devices to
devices file entries using PVID, looking at all disks
on the system with the same serial number.
2022-11-07 08:56:02 -06:00
David Teigland
13c63f0cfa lvmdevices: use deviceidtype option strictly
Only use the device id type specified by --deviceidtype,
and fail if that type is not available for the device.
2022-10-10 11:47:29 -05:00
David Teigland
79e67fc5e4 device id: add new types using values from vpd_pg83
The new device_id types are: wwid_naa, wwid_eui, wwid_t10.
The new types use the specific wwid type in their name.
lvm currently gets the values for these types by reading
the device's vpd_pg83 sysfs file (this could change in the
future if better methods become available for reading the
values.)

If a device is added to the devices file using one of these
types, prior versions of lvm will not recognize the types
and will be unable to use the devices.

When adding a new device, lvm continues to first use sys_wwid
from the sysfs wwid file.  If the device has no sysfs wwid file,
lvm now attempts to use one of the new types from vpd_pg83.

If a devices file entry with type sys_wwid does not match a
given device's sysfs wwid file, the sys_wwid value will also
be compared to that device's other wwids from its vpd_pg83 file.
If the kernel changes the wwid type reported from the sysfs
wwid file, e.g. from a device's t10 id to its naa id, then lvm
should still be able to match it correctly using the vpd_pg83
data which will include both ids.
2022-10-10 11:47:29 -05:00
David Teigland
380ab3f45c device id wwid adjustments
Move the functions handling dev wwids.

Add dev flags indicating that wwids have been read from
sysfs wwid file or sysfs vpd_pg83 file.  This can be
used to avoid rereading these.

Improve filter-mpath search for a device's wwid in
/etc/multipath/wwids, to avoid unnecessary rereading
of wwids from sysfs files.

Type 8 wwids from vpd_pg83 with naa or eui names should be
saved as those types.
2022-10-10 11:47:29 -05:00
David Teigland
3b0f9cec7e filter-mpath: get wwids from sysfs vpd_pg83
to compare with wwids in /etc/multipath/wwids when
excluding multipath components.  The wwid printed
from the sysfs wwid file may not be the wwid used
in multipath wwids.  Save the wwids found for each
device on dev->wwids to avoid repeating reading
and parsing the sysfs files.
2022-06-08 15:06:01 -05:00
David Teigland
fb7698b0ce lvmdevices: --deldev using device id
When used with --deviceidtype, --deldev can specify
a device id to remove.
2022-04-06 12:51:34 -05:00
David Teigland
6e22be20c6 devices file: warn about missing multipath entry
Warn if a scsi device is listed in the devices file that
is used by a multipath device that is not listed.  This
will happen if a scsi device is listed in the devices
file and then an mpath device is set up to use it.

The way to correct this would be to remove the devices
file entry for the component device and add a new entry
for the multipath device.
2022-04-01 13:38:21 -05:00
David Teigland
3fce6a81f8 lvmdevices: make deldev work for missing device 2022-02-03 16:56:03 -06:00
David Teigland
212b1fc529 devices: exclude multipath components based on matching wwid
If multipath component devices get through the filter and
cause lvm to see duplicate PVs, then check the wwid of the
devs and drop the component devices as if they had been
filtered.  If a dm mpath device was found among the duplicates
then use that as the PV, otherwise do not use any of the
components as the PV.

"duplicate PVs" associated with multipath configs will no
longer stop commands from working.
2021-11-18 17:41:00 -06:00
David Teigland
33e47182f7 pvscan: only add device args to dev cache
Optimize the common pvscan --cache command by only adding
the necessary devs to dev-cache.
2021-10-19 17:13:57 -05:00
David Teigland
8e62cbb18e device_id: update stacked PVs for vgchange uuid
If a VG uuid is changed, update the device_id of any
PVs stacked on LVs in the changed VG.
2021-10-04 16:54:44 -05:00
David Teigland
9048565093 devices: rework libudev usage
related to config settings:
  obtain_device_info_from_udev (controls if lvm gets
    a list of devices from readdir /dev or from libudev)
  external_device_info_source (controls if lvm asks
    libudev for device information)

. Make the obtain_device_list_from_udev setting
  affect only the choice of readdir /dev vs libudev.
  The setting no longer controls if udev is used for
  device type checks.

. Change obtain_device_list_from_udev default to 0.
  This helps avoid boot timeouts due to slow libudev
  queries, avoids reported failures from
  udev_enumerate_scan_devices, and avoids delays from
  "device not initialized in udev database" errors.
  Even without errors, for a system booting with 1024 PVs,
  lvm2-pvscan times improve from about 100 sec to 15 sec,
  and the pvscan command from about 64 sec to about 4 sec.

. For external_device_info_source="none", remove all
  libudev device info queries, and use only lvm
  native device info.

. For external_device_info_source="udev", first check
  lvm native device info, then check libudev info.

. Remove sleep/retry loop when attempting libudev
  queries for device info.  udev info will simply
  be skipped if it's not immediately available.

. Only set up a libdev connection if it will be used by
  obtain_device_list_from_udev/external_device_info_source.

. For native multipath component detection, use
  /etc/multipath/wwids.  If a device has a wwid
  matching an entry in the wwids file, then it's
  considered a multipath component.  This is
  necessary to natively detect multipath
  components when the mpath device is not set up.
2021-07-13 11:11:23 -05:00
David Teigland
83fe6e720f device usage based on devices file
The LVM devices file lists devices that lvm can use.  The default
file is /etc/lvm/devices/system.devices, and the lvmdevices(8)
command is used to add or remove device entries.  If the file
does not exist, or if lvm.conf includes use_devicesfile=0, then
lvm will not use a devices file.  When the devices file is in use,
the regex filter is not used, and the filter settings in lvm.conf
or on the command line are ignored.

LVM records devices in the devices file using hardware-specific
IDs, such as the WWID, and attempts to use subsystem-specific
IDs for virtual device types.  These device IDs are also written
in the VG metadata.  When no hardware or virtual ID is available,
lvm falls back using the unstable device name as the device ID.
When devnames are used, lvm performs extra scanning to find
devices if their devname changes, e.g. after reboot.

When proper device IDs are used, an lvm command will not look
at devices outside the devices file, but when devnames are used
as a fallback, lvm will scan devices outside the devices file
to locate PVs on renamed devices.  A config setting
search_for_devnames can be used to control the scanning for
renamed devname entries.

Related to the devices file, the new command option
--devices <devnames> allows a list of devices to be specified for
the command to use, overriding the devices file.  The listed
devices act as a sort of devices file in terms of limiting which
devices lvm will see and use.  Devices that are not listed will
appear to be missing to the lvm command.

Multiple devices files can be kept in /etc/lvm/devices, which
allows lvm to be used with different sets of devices, e.g.
system devices do not need to be exposed to a specific application,
and the application can use lvm on its own set of devices that are
not exposed to the system.  The option --devicesfile <filename> is
used to select the devices file to use with the command.  Without
the option set, the default system devices file is used.

Setting --devicesfile "" causes lvm to not use a devices file.

An existing, empty devices file means lvm will see no devices.

The new command vgimportdevices adds PVs from a VG to the devices
file and updates the VG metadata to include the device IDs.
vgimportdevices -a will import all VGs into the system devices file.

LVM commands run by dmeventd not use a devices file by default,
and will look at all devices on the system.  A devices file can
be created for dmeventd (/etc/lvm/devices/dmeventd.devices)  If
this file exists, lvm commands run by dmeventd will use it.

Internal implementaion:

- device_ids_read - read the devices file
  . add struct dev_use (du) to cmd->use_devices for each devices file entry
- dev_cache_scan - get /dev entries
  . add struct device (dev) to dev_cache for each device on the system
- device_ids_match - match devices file entries to /dev entries
  . match each du on cmd->use_devices to a dev in dev_cache, using device ID
  . on match, set du->dev, dev->id, dev->flags MATCHED_USE_ID
- label_scan - read lvm headers and metadata from devices
  . filters are applied, those that do not need data from the device
  . filter-deviceid skips devs without MATCHED_USE_ID, i.e.
    skips /dev entries that are not listed in the devices file
  . read lvm label from dev
  . filters are applied, those that use data from the device
  . read lvm metadata from dev
  . add info/vginfo structs for PVs/VGs (info is "lvmcache")
- device_ids_find_renamed_devs - handle devices with unstable devname ID
  where devname changed
  . this step only needed when devs do not have proper device IDs,
    and their dev names change, e.g. after reboot sdb becomes sdc.
  . detect incorrect match because PVID in the devices file entry
    does not match the PVID found when the device was read above
  . undo incorrect match between du and dev above
  . search system devices for new location of PVID
  . update devices file with new devnames for PVIDs on renamed devices
  . label_scan the renamed devs
- continue with command processing
2021-02-23 16:43:32 -06:00