lvm2/man/lvmreport.7.in

.TH "LVMREPORT" "7" "LVM TOOLS #VERSION#" "Red Hat, Inc" "\""

.SH NAME
lvmreport \(em LVM reporting and related features

.SH DESCRIPTION
LVM uses single reporting infrastructure that sets standard on LVM command's
output and it provides wide range of configuration settings and command line
options to customize report and filter the report's output.

.SH Categorization based on reporting facility

Based on functionality, commands which make use of the reporting infrastructure
are divided in two groups:
.IP \fBReport-oriented commands\fP
These commands inform about current LVM state and their primary role is to
display this information in compendious way. To make a distinction, we will
name this report as \fBmain report\fP. The set of report-only commands include:
pvs, vgs, lvs, pvdisplay, vgdisplay, lvdisplay, lvm devtypes, lvm fullreport.
For further information about main report, see \fBmain report specifics\fP.
.IP \fBProcessing-oriented commands\fP
These commands are responsible for changing LVM state and they do not contain
any main report as identified for report-oriented commands, they only perform
some kind of processing. The set of processing-oriented commands includes:
pvcreate, vgcreate, lvcreate, pvchange, vgchange, lvchange, pvremove, vgremove,
lvremove, pvresize, vgextend, vgreduce, lvextend, lvreduce, lvresize, lvrename,
pvscan, vgscan, lvscan, pvmove, vgcfgbackup, vgck, vgconvert, vgexport,
vgimport, vgmknodes.

.RE
If enabled, so called \fBlog report\fP is either displayed solely
(for processing-oriented commands) or in addition to main report
(for report-oriented commands). The log report contains a log of operations,
messages and per-object status with complete object identification collected
during LVM command execution. See \fBlog report specifics\fP for more
information about this report type.


.SH Terms

When describing reporting functionality and features in this text, we will
use terms \fBrow\fP and \fBcolumn\fP. By row we mean series of values reported
for single entity (for example single PV, VG or LV). Each value from the row
then belongs to a column of certain type. The columns have \fBcolumn headings\fP
which are short descriptions for the columns. The columns are referenced by
\fBcolumn names\fP. Please note that this text is also using term \fBfield\fP
interchangeably with the term \fBcolumn\fP. Most of the time the term columns
is abbreviated as \fBcol\fP in configuration.

.SH Common report configuration settings and command line options

There are common configuration settings and command line options which apply
to both \fBmain report\fP and \fBlog report\fP. Following lists contain all
of them, separated into groups based on their use.

.RS
\fBCommon configuration settings:\fP

.RS

.IP \[bu] 3
Changing report output format, composition and other output modifiers:
.RS
.IP - 3
global/units
.IP - 3
global/suffix
.IP - 3
report/output_format
.IP - 3
report/compact_output
.IP - 3
report/compact_output_cols
.IP - 3
report/aligned
.IP - 3
report/headings
.IP - 3
report/separator
.IP - 3
report/list_item_separator
.IP - 3
report/prefixes
.IP - 3
report/quoted
.IP - 3
report/columns_as_rows
.IP - 3
report/binary_values_as_numeric
.IP - 3
report/time_format
.IP - 3
report/mark_hidden_devices
.IP - 3
report/two_word_unknown_device
.RE

.IP \[bu] 3
Special settings
.RS
.IP - 3
report/buffered
.RE

.RE

.RE

This document does not describe these settings in more detail - if you need
detailed information, including values which are accepted for the settings,
please run \fBlvmconfig --type default --withcomments <setting>\fP. There are
more configuration settings in addition to the common set listed above, but
they are specific to either \fBmain report\fP or \fBlog report\fP,
see \fBmain report specifics\fP and \fBlog report specifics\fP for
these settings. Besides configuring reports globally by using configuration
settings, there are also command line options you can use to extend, override
or further specify the report configuration.

.RS
\fBCommon command line options:\fP

.RS

.IP \[bu] 3
Definition of the set set of fields to use
.RS
.IP - 3
--options|-o FieldSet
.br
Field set to use. See \fBmain report specifics\fP and
\fBlog report specifics\fP for information about field sets configured with
global configuratin settings that this option overrides.
.IP - 3
--options|-o+ FieldSet
.br
Fields to include to current field set. See \fBmain report specifics\fP\ and
\fBlog report specifics\fP for information about field sets configured with
global configuration settings that this option extends.
.IP - 3
--options|-o- FieldSet
.br
Fields to exclude from current field set. See \fBmain report specifics\fP and
\fBlog report specifics\fP for information about field sets configured with
global configuration settings that this option reduces.
.IP - 3
--options|-o# FieldSet
.br
Compaction of unused fields. Overrides report/compact_output_cols configuration
setting.
.RE

.IP \[bu] 3
Sorting
.RS
.IP - 3
--sort|-O+ FieldSet
.br
Fields to sort by in ascending order. See \fBmain report specifics\fP and
\fBlog report specifics\fP for information about field sets configured with
global configuration settings that this option overrides.
.IP - 3
--sort|-O- FieldSet
.br
Fields to sort by in descending order. See \fBmain report specifics\fP and
\fBlog report specifics\fP for information about fields sets configured with
global configuration settings that this options overrides.
.RE

.IP \[bu] 3
Selection
.RS
.IP - 3
--select|-S Selection
.br
Define selection criteria for report output. For \fBlog report\fP, this also
overrides log/command_log_selection configuration setting, see also
\fBlog report specifics\fP.
.RE

.IP \[bu] 3
Changing output format and composition
.RS
.IP - 3
--reportformat
.br
Overrides report/output_format configuration setting.
.IP - 3
--aligned
.br
Overrides report/aligned configuration setting.
.IP - 3
--binary
.br
Overrides report/binary_values_as_numeric configuration setting.
.IP - 3
--nameprefixes
.br
Overrides report/prefixes configuration setting.
.IP - 3
--noheadings
.br
Overrides report/noheadings configuration setting.
.IP - 3
--nosuffix
.br
Overrides global/suffix configuration setting.
.IP - 3
--rows
.br
Overrides report/columns_as_rows configuration setting.
.IP - 3
--separator
.br
Overrides report/separator configuration setting.
.IP - 3
--units
.br
Overrides global/units configuration setting.
.IP - 3
--unquoted
.br
Overrides report/quoted configuration setting.
.RE

.IP \[bu] 3
Special options
.RS
.IP - 3
--configreport \fBReportName\fP
.br
This defines the \fBReportName\fP for which any subsequent -o|--columns,
-O|--sort or -S|--select applies to. See also \fBmain report specifics\fP
and \fBlog report specifics\fP for possible \fBReportName\fP values.
.IP - 3
--logonly
.br
When an LVM command contains both \fBmain report\fP and \fBlog report\fP,
this option suppresses the \fBmain report\fP output and it causes the
\fBlog report\fP output to be displayed only.
.IP - 3
--unbuffered
.br
Overrides report/bufffered configuration setting.
.RE

.RE

.RE

The \fBFieldSet\fP mentioned in the lists above is a set of field names where
each field name is delimited by "," character. Field set definition, sorting
and selection may be repeated on command line (-o+/-o- includes/excludes fields
to/from current list, for all the other repeatable options, the last value
typed for the option on the command line is used). The \fBSelection\fP
is a string with \fBselection criteria\fP, see also \fBSelection\fP paragraph
below for more information about constructing these criteria.


.SH Main report specifics

The \fBmain report\fP currently encompasses these distinct subtypes, referenced
by their name - \fBReportName\fP as listed below. The command in parenthesis is
representative command that uses the main report subtype by default.
Each subtype has its own configuration setting for global field set definition
as well as sort field definition (listed below each individual \fBReportName\fP):

.RS

.IP \[bu] 3
\fBpv\fP representing report about Physical Volumes (\fBpvs\fP)
.RS
.IP - 3
report/pvs_cols
.IP - 3
report/pvs_sort
.RE

.IP \[bu] 3
\fBpvseg\fP representing report about Physical Volume Segments (\fBpvs --segments\fP)
.RS
.IP - 3
report/pvseg_cols
.IP - 3
report/pvseg_sort
.RE

.IP \[bu] 3
\fBvg\fP representing report about Volume Groups (\fBvgs\fP)
.RS
.IP - 3
report/vgs_cols
.IP - 3
report/vgs_sort
.RE

.IP \[bu] 3
\fBlv\fP representing report about Logical Volumes (\fBlvs\fP)
.RS
.IP - 3
report/lvs_cols
.IP - 3
report/lvs_sort
.RE

.IP \[bu] 3
\fBseg\fP representing report about Logical Volume Segments (\fBlvs --segments\fP)
.RS
.IP - 3
report/segs_cols
.IP - 3
report/segs_sort
.RE

.IP \[bu] 3
\fBfull\fP representing report combining all of the above as a whole (\fBlvm fullreport\fP)
.RS
.IP - 3
report/pvs_cols_full
.IP - 3
report/pvs_sort_full
.IP - 3
report/pvsegs_cols_full
.IP - 3
report/pvseg_sort_full
.IP - 3
report/vgs_cols_full
.IP - 3
report/vgs_sort_full
.IP - 3
report/lvs_cols_full
.IP - 3
report/lvs_sort_full
.IP - 3
report/segs_cols_full
.IP - 3
report/segs_sort_full
.RE

.IP \[bu] 3
\fBdevtype\fP representing report about device types (\fBlvm devtypes\fP)
.RS
.IP - 3
report/devtypes_cols
.IP - 3
report/devtypes_sort
.RE

.RE

Use \fBpvs, vgs, lvs -o help\fP or \fBlvm devtypes -o help\fP to get complete
list of fields that you can use for main report. The list of fields in the
help output is separated in groups based on which report type they belong to.
Note that LVM can change final report type used if fields from different
groups are combined together. Some of these combinations are not allowed in
which case LVM will issue an error.

For all main report subtypes except \fBfull\fP, it's not necessary to use
\fB--configreport ReportName\fP to denote which report any subsequent
\fB-o, -O or -S\fP option applies to as they always apply to the single main
report type. Currently, \fBlvm fullreport\fP is the only command that
includes more than one \fBmain report\fP subtype. Therefore, the --configreport
is particularly suitable for the full report if you need to configure each of
its subreports in a different way.


.SH Log report specifics

You can enable log report with \fBlog/report_command_log\fP configuration
setting - this functionality is disabled by default. The \fBlog report\fP
contains a log collected during LVM command execution and then the log is
displayed just like any other report known from main report. There is only one
log report subtype as shown below together with related configuration settings
for fields, sorting and selection:

.RS

.IP \[bu] 3
\fBlog\fP representing log report
.RS
.IP - 3
log/command_log_cols
.IP - 3
log/command_log_sort
.IP - 3
log/command_log_selection
.RE

.RE

You always need to use \fB--configreport log\fP together with \fB-o|--options,
-O|--sort or -S|--selection\fP to override configuration settings directly on
command line for \fBlog report\fP. When compared to \fBmain report\fP, in
addition to usual configuration settings for report fields and sorting, the
\fBlog report\fP has also configuration option for selection -
\fBreport/command_log_selection\fP. This configuration setting is provided for
convenience so it's not necessary to use \fB-S|--select\fP on command line
each time an LVM command is executed and we need the same selection criteria
to be applied for \fBlog report\fP. Default selection criteria used for
\fBlog report\fP are
\fBlog/command_log_selection="!(log_type=status && message=success)"\fP.
This means that, by default, \fBlog report\fP doesn't display status messages
about successful operation and it displays only rows with error, warning,
print-type messages and messages about failure states (for more information,
see \fBlog report content\fP below).

.B Log report coverage
.br
Currently, when running LVM commands directly (not in LVM shell), the log
report covers command's \fBprocessing stage\fP which is the moment when LVM
entities are iterated and processed one by one. It does not cover any command
initialization nor command finalization stage. If there is any message issued
out of log report's coverage range, such message goes directly to output,
bypassing the \fBlog report\fP. By default, that is \fBstandard error output\fP
for error and warning messages and \fBstandard output\fP for common print-like
messages.

When running LVM commands in \fBLVM shell\fP, the log report covers the whole
LVM command's execution, including command's \fBprocessing\fP as well as
\fBinitialization\fP and \fBfinalization stage\fP. So from this point of view,
the log report coverage is complete for executed LVM commands. Note that there
are still a few moments when LVM shell needs to initialize itself before it
even enters the main loop in which it executes LVM commands. Also, there is a
moment when \fBLVM shell\fP needs to prepare \fBlog report\fP properly for
next command executed in the shell and then, after the command's run, the shell
needs to display the log report for that recently executed command. If there
is a failure or any other message issued during this time, the LVM will bypass
\fBlog report\fP and display messages on output directly.

For these reasons and for completeness, it's not possible to rely fully on
\fBlog report\fP as the only indicator of LVM command's status and the only
place where all messages issued during LVM command execution are collected.
You always need to check whether the command has not failed out of log
report's range by checking the non-report output too.

To help with this, LVM can separate output which you can then redirect to
any \fBcustom file descriptor\fP that you prepare before running an LVM
command or LVM shell and then you make LVM to use these file descriptors
for different kinds of output by defining environment variables with file
descriptor numbers. See also \fBLVM_OUT_FD\fP, \fBLVM_ERR_FD\fP and
\fBLVM_REPORT_FD\fP environment variable description in \fBlvm\fP(8)
man page.

Also note that, by default, reports use the same file descriptor as
common print-like messages, which is \fBstandard output\fP. If you plan to
use \fBlog report\fP in your scripts or any external tool, you should use
\fBLVM_OUT_FD\fP, \fBLVM_ERR_FD\fP and \fBLVM_REPORT_FD\fP to separate all
output types to different file descriptors. For example, with bash, that
would be:

.RS
LVM_OUT_FD=3 LVM_ERR_FD=4 LVM_REPORT_FD=5 <lvm command> 3>out_file 4>err_file 5>report_file
.RE

Where the <lvm_command> is either direct LVM command or LVM shell.
You can collect all three types of output in particular files then.

.B Log report content
.br
Each item in the log report consists of these set of fields providing various
information:

.RS

.IP \[bu] 3
Basic information (mandatory):
.RS
.IP - 3
log_seq_num
.br
Item sequence number. The sequence number is unique for each log item and it
increases in the order of the log items as they appeared during LVM command
execution.

.IP - 3
log_type
.br
Type of log for the item. Currently, these types are used:
.RS
.IP
\fBstatus\fP for any status information that is logged
.IP
\fBprint\fP for any common message printed while the log is collected
.IP
\fBerror\fP for any error message printed while the log is collected
.IP
\fBwarn\fP for any warning message printed while the log is collected
.RE

.IP - 3
log_context
.br
Context of the log for the item. Currently, two contexts are identified:
.RS
.IP
\fBshell\fP for the log collected in the outermost code before and after
executing concrete LVM commands
.IP
\fBprocessing\fP for the log collected while processing LVM entities during
LVM command execution
.RE

.RE

.IP \[bu] 3
Message (mandatory):
.RS
.IP - 3
log_message
.br
Any message associated with current item. For \fBstatus\fP log type,
the message contains either \fBsuccess\fP or \fBfailure\fP denoting
current state. For \fBprint\fP, \fBerror\fP and \fBwarn\fP log types,
the message contains the exact message of that type that got issued.
.RE

.IP \[bu] 3
Object information (used only if applicable):
.RS
.IP - 3
log_object_type field
.br
Type of the object processed. Currently, these object types are recognized:
.RS
.IP
\fBcmd\fP for command as a whole
.IP
\fBorphan\fP for processing group of PVs not in any VG yet
.IP
\fBpv\fP for PV processing
.IP
\fBlabel\fP for direct PV label processing (without VG metadata)
.IP
\fBvg\fP for VG processing
.IP
\fBlv\fP for LV processing
.RE

.IP - 3
log_object_name
.br
Name of the object processed.

.IP - 3
log_object_id
.br
ID of the object processed.

.IP - 3
log_object_group
.br
A group where the processed object belongs to.

.IP - 3
log_object_group_id
.br
An ID of a group where the processed object belongs to.
.RE

.IP \[bu] 3
Numeric status (used only if applicable)
.RS
.IP - 3
log_errno
.br
Error number associated with current item.
.IP - 3
log_ret_code
.br
Rreturn code associated with current item.
.RE

.RE


You can also run \fB<lvm_command> --configreport log -o help\fP to
to display complete list of fields that you may use for the \fBlog report\fP.

.SH Selection
Selection is used for a report to display only rows that match
\fBselection criteria\fP. All rows are displayed with the additional
\fBselected\fP field (\fB-o selected\fP) displaying 1 if the row matches the
\fISelection\fP and 0 otherwise. The \fBselection criteria\fP are a set of
\fBstatements\fP combined by \fBlogical and grouping operators\fP.
The \fBstatement\fP consists of a \fBfield\fP name for which a set of valid
\fBvalues\fP is defined using \fBcomparison operators\fP. For complete list
of fields names that you can use in selection, see the output of
\fB<lvm_command> -S help\fP. The help output also contains type of values
that each field displays enclosed in brackets.

.B List of operators recognized in selection criteria
.RS
.IP \[bu] 3
Comparison operators (cmp_op)
.RS
.IP
\fB=~\fP matching regular expression.
.IP
\fB!~\fP not matching regular expression.
.IP
\fB= \fP equal to.
.IP
\fB!=\fP not equal to.
.IP
\fB>=\fP greater than or equal to.
.IP
\fB> \fP greater than
.IP
\fB<=\fP less than or equal to.
.IP
\fB< \fP less than.
.RE

.IP \[bu] 3
Binary logical operators (cmp_log)
.RS
.IP
\fB&&\fP all fields must match
.IP
\fB, \fP all fields must match
.IP
\fB||\fP at least one field must match
.IP
\fB# \fP at least one field must match
.RE

.IP \[bu] 3
Unary logical operators
.RS
.IP
\fB! \fP logical negation
.RE

.IP \[bu] 3
Grouping operators
.RS
.IP
\fB( \fP left parenthesis
.IP
\fB) \fP right parenthesis
.IP
\fB[ \fP list start
.IP
\fB] \fP list end
.IP
\fB{ \fP list subset start
.IP
\fB} \fP list subset end
.RE

.RE

.B Field types and selection operands
.br
Field type restricts the set of operators and values that you may use with
the field when defining selection criteria. You can see field type for each
field if you run \fB<lvm command> -S help\fP where you can find the type name
enclosed in square brackets. Currently, LVM recognizes these field types in
reports:

.RS
.IP \[bu] 3
\fBstring\fP for set of characters (for each string field type, you can use
either string or regular expression - regex for the value used in selection
criteria)
.IP \[bu] 3
\fBstring list\fP for set of strings
.IP \[bu] 3
\fBnumber\fP for integer value
.IP \[bu] 3
\fBsize\fP for integer or floating point number with size unit suffix
(see also \fBlvcreate\fP(8) man page and description for "-L|--size"
option for the list of recognized suffixes)
.IP \[bu] 3
\fBpercent\fP for floating point number with or without "%" suffix
(e.g. 50 or 50%)
.IP \[bu] 3
\fBtime\fP for time values
.RE

When using \fBstring list\fP in selection criteria, there are several ways
how LVM can match string list fields from report, depending on what list
grouping operator is used and what item separator is used within that set
of items. Also, note that order of items does not matter here.

.RS
.IP \[bu] 3
\fBmatching the set strictly\fP where all items must match - use [ ], e.g.
["a","b","c"]
.IP \[bu] 3
\fBmatching a subset of the set\fP - use { } with "," or "&&" as item
delimiter, e.g. {"a","b","c"}
.IP \[bu] 3
\fBmatching an intersection with the set\fP - use { } with "#" or
"||" as item delimiter, e.g. {"a" || "b" || "c"}
.RE

When using \fBtime\fP in your selection criteria, LVM can recognize various
time formats using standard, absolute or freeform expressions. For examples
demonstrating time expressions in selection criteria, see \fBEXAMPLES\fP section.

.RS

.IP \[bu] 3
\fBStandard time format\fP

.RS
.IP - 3
date
.RS
.IP
YYYY-MM-DD
.IP
YYYY-MM, auto DD=1
.IP
YYYY, auto MM=01 and DD=01
.RE

.IP - 3
time
.RS
.IP
hh:mm:ss
.IP
hh:mm, auto ss=0
.IP
hh, auto mm=0, auto ss=0
.RE

.IP - 3
timezone
.RS
.IP
+hh:mm or -hh:mm
.IP
+hh or -hh
.RE

The full date/time specification is YYYY-MM-DD hh:mm:ss. Users are able
to leave date/time parts from right to left. Whenever these parts are left out,
a range is assumed automatically with second granularity. For example:

.RS
.IP
"2015-07-07 9:51" means range of "2015-07-07 9:51:00" - "2015-07-07 9:51:59".
.IP
"2015-07" means range of "2015-07-01 0:00:00" - "2015-07-31 23:59:59"
.IP
"2015" means range of "2015-01-01 0:00:00" - "2015-12-31 23:59:59"
.RE

.RE

.IP \[bu] 3
\fBAbsolute time format\fP

Absolute time is defined as number of seconds since the Epoch
(1970:01:01 00:00 +00:00).

.RS
.IP - 3
@seconds
.RE

.IP \[bu] 3
\fBFreeform time format\fP
.RS
.IP - 3
weekday names ("Sunday" - "Saturday" or abbreviated as "Sun" - "Sat")
.IP - 3
labels for points in time ("noon", "midnight")
.IP - 3
labels for a day relative to current day ("today", "yesterday")
.IP - 3
points back in time with relative offset from today (N is a number)
.RS
.IP
"N" "seconds" / "minutes" / "hours" / "days" / "weeks" / "years" "ago"
.IP
"N" "secs" / "mins" / "hrs" ... "ago"
.IP
"N" "s" / "m" / "h" ... "ago"
.RE
.IP - 3
time specification either in hh:mm:ss format or with AM/PM suffixes
.IP - 3
month names ("January" - "December" or abbreviated as "Jan" - "Dec")
.RE

.RE

.B Informal grammar specification
.RS
.IP
.BR STATEMENT " = " column " cmp_op " VALUE " | " \%STATEMENT " log_op " STATEMENT " | " \%(STATEMENT) " | " \%!(STATEMENT)
.IP
.BR VALUE " = " [VALUE " log_op " VALUE]
.br
For list-based types: string list. Matches strictly.
The log_op must always be of one type within the whole list value.
.IP
.BR VALUE " = " {VALUE " log_op " VALUE}
.br
For list-based types: string list. Matches a subset.
The log_op must always be of one type within the whole list value.
.IP
.BR VALUE " = " value
.br
For scalar types: number, size, percent, string (or string regex).
.RE

.SH EXAMPLES

.SS Basic usage

We start our examples with default configuration - \fBlvmconfig\fP(8) is
helpful command to display configuration settings which are currently used,
including all configuration related to reporting. We will use it throughout
examples below to display current configuration.

.nf
# lvmconfig --type full global/units global/suffix \\
   report/output_format  report/compact_output \\
   report/compact_output_cols report/aligned \\
   report/headings report/separator \\
   report/list_item_separator report/prefixes \\
   report/quoted report/columns_as_rows \\
   report/binary_values_as_numeric report/time_format \\
   report/mark_hidden_devices report/two_word_unknown_device \\
   report/buffered
units="h"
suffix=1
output_format="basic"
compact_output=0
compact_output_cols=""
aligned=1
headings=1
separator=" "
list_item_separator=","
prefixes=0
quoted=1
columns_as_rows=0
binary_values_as_numeric=0
time_format="%Y-%m-%d %T %z"
mark_hidden_devices=1
two_word_unknown_device=0
buffered=1
.fi

Also, we start with simple LVM layout with two PVs (/dev/sda, /dev/sdb),
VG (vg) and two LVs (lvol0 and lvol1) in the VG. We display all possible
reports as single commands here, see also \fBpvs\fP(8), \fBvgs\fP(8),
\fBlvs\fP(8) man pages for more information. The field set for each report
type is configured with configuration settings as we already mentioned in
\fBmain report specifics\fP section in this man page.

.nf
# lvmconfig --type full report/pvs_cols report/pvs_sort \\
   report/pvsegs_cols report/pvsegs_sort report/vgs_cols \\
   report/vgs_sort report/lvs_cols report/lvs_sort \\
   report/segs_cols report/segs_sort
pvs_cols="pv_name,vg_name,pv_fmt,pv_attr,pv_size,pv_free"
pvs_sort="pv_name"
pvsegs_cols="pv_name,vg_name,pv_fmt,pv_attr,pv_size,pv_free,
             pvseg_start,pvseg_size"
pvsegs_sort="pv_name,pvseg_start"
vgs_cols="vg_name,pv_count,lv_count,snap_count,vg_attr,vg_size,vg_free"
vgs_sort="vg_name"
lvs_cols="lv_name,vg_name,lv_attr,lv_size,pool_lv,origin,move_pv,
          mirror_log,copy_percent,convert_lv"
lvs_sort="vg_name,lv_name"
segs_cols="lv_name,vg_name,lv_attr,stripes,segtype,seg_size"
segs_sort="vg_name,lv_name,seg_start"
.fi

.nf
# pvs
  PV         VG Fmt  Attr PSize   PFree 
  /dev/sda   vg lvm2 a--  100.00m 88.00m
  /dev/sdb   vg lvm2 a--  100.00m 92.00m

# pvs --segments
  PV         VG Fmt  Attr PSize   PFree  Start SSize
  /dev/sda   vg lvm2 a--  100.00m 88.00m     0     1
  /dev/sda   vg lvm2 a--  100.00m 88.00m     1     1
  /dev/sda   vg lvm2 a--  100.00m 88.00m     2     1
  /dev/sda   vg lvm2 a--  100.00m 88.00m     3    22
  /dev/sdb   vg lvm2 a--  100.00m 92.00m     0     1
  /dev/sdb   vg lvm2 a--  100.00m 92.00m     1     1
  /dev/sdb   vg lvm2 a--  100.00m 92.00m     2    23

# vgs
  VG #PV #LV #SN Attr   VSize   VFree  
  vg   2   2   0 wz--n- 200.00m 180.00m

# lvs
  LV    VG Attr       LSize Pool Origin Move Log Cpy%Sync Convert
  lvol0 vg -wi-a----- 4.00m                                    
  lvol1 vg rwi-a-r--- 4.00m                      100.00          

# lvs --segments
  LV    VG Attr       #Str Type   SSize
  lvol0 vg -wi-a-----    1 linear 4.00m
  lvol1 vg rwi-a-r---    2 raid1  4.00m
.fi

We will use \fBreport/lvs_cols\fP and \fBreport/lvs_sort\fP configuration
settings to define our own list of fields to use and to sort by that is
different from defaults. You can do this for other reports in same manner
with \fBreport/{pvs,pvseg,vgs,seg}_{cols,sort}\fP configuration settings.
Also note that in the example below, we don't display the "lv_time" field
even though we're using it for sorting - this is allowed.

.nf
# lvmconfig --type full report/lvs_cols report/lvs_sort
lvs_cols="lv_name,lv_size,origin,pool_lv,copy_percent"
lvs_sort="-lv_time"

# lvs
  LV    LSize Origin Pool Cpy%Sync
  lvol1 4.00m             100.00  
  lvol0 4.00m  
.fi

You can use \fB-o|--options\fP command line option to override current
configuration directly on command line.

.nf
# lvs -o lv_name,lv_size
  LV    LSize
  lvol1 4.00m
  lvol0 4.00m

# lvs -o+lv_layout
  LV    LSize Origin Pool Cpy%Sync Layout    
  lvol1 4.00m             100.00   raid,raid1
  lvol0 4.00m                      linear    

# lvs -o-origin
  LV    LSize Pool Cpy%Sync
  lvol1 4.00m      100.00  
  lvol0 4.00m              

# lvs -o lv_name,lv_size,origin -o+lv_layout -o-origin -O lv_name
  LV    LSize Layout    
  lvol0 4.00m linear    
  lvol1 4.00m raid,raid1
.fi

You can obtain the same information with single command where all the
information about PVs, PV segments, LVs and LV segments are obtained
per VG under a single VG lock for consistency, see also \fBlvm fullreport\fP(8)
man page for more information. The fullreport has its own configuration
settings to define field sets to use, similar to individual reports as
displayed above, but configuration settings have "_full" suffix now.
This way, it's possible to configure different sets of fields to display
and to sort by for individual reports as well as the full report.

.nf
# lvmconfig --type full report/pvs_cols_full \\
   report/pvs_sort_full report/pvsegs_cols_full \\
   report/pvsegs_sort_full report/vgs_cols_full \\
   report/vgs_sort_full report/lvs_cols_full \\
   report/lvs_sort_full report/segs_cols_full \\
   report/segs_sort_full
pvs_cols_full="pv_name,vg_name"
pvs_sort_full="pv_name"
pvsegs_cols_full="pv_name,pvseg_start,pvseg_size"
pvsegs_sort_full="pv_uuid,pvseg_start"
vgs_cols_full="vg_name"
vgs_sort_full="vg_name"
lvs_cols_full="lv_name,vg_name"
lvs_sort_full="vg_name,lv_name"
segs_cols_full="lv_name,seg_start,seg_size"
segs_sort_full="lv_uuid,seg_start"
.fi

.nf
# lvm fullreport
  VG
  vg
  PV         VG
  /dev/sda   vg
  /dev/sdb   vg
  LV    VG
  lvol0 vg
  lvol1 vg
  PV         Start SSize
  /dev/sda       0     1
  /dev/sda       1     1
  /dev/sda       2     1
  /dev/sda       3    22
  /dev/sdb       0     1
  /dev/sdb       1     1
  /dev/sdb       2    23
  LV    Start SSize
  lvol0    0  4.00m
  lvol1    0  4.00m
.fi

.SS Automatic output compaction

If you look at the lvs output above, you can see that the report also contains
fields for which there is no information to display (e.g. the columns under
"Origin" and "Pool" heading - the "origin" and "pool_lv" fields). LVM can
automatically compact report output so such fields are not included in final
output. To enable this feature and to compact all fields, use
\fBreport/compact_output=1\fP in your configuration.

.nf
# lvmconfig --type full report/compact_output
compact_output=1

# lvs
  LV    LSize Cpy%Sync
  lvol1 4.00m 100.00  
  lvol0 4.00m  

# lvs vg/lvol0
  LV    LSize 
  lvol0 4.00m
.fi

Alternatively, you can define which fields should be compacted by configuring
\fBreport/compact_output_cols\fP configuration setting (or \fB-o|--options #\fP
command line option).

.nf
# lvmconfig --type full report/compact_output report/compact_output_cols
compact_output=0
compact_output_cols="origin"

# lvs
  LV    LSize Pool Cpy%Sync
  lvol1 4.00m      100.00  
  lvol0 4.00m    

# lvs vg/lvol0
  LV    LSize Pool 
  lvol0 4.00m    

# lvs -o#pool_lv        
  LV    LSize Origin Cpy%Sync
  lvol1 4.00m        100.00  
  lvol0 4.00m                
.fi

We will use \fBreport/compact_output=1\fP for subsequent examples.

.SS Further formatting options

By default, LVM displays sizes in reports in human-readable form which means
that the most suitable unit is used so it's easy to read. You can use
\fBreport/units\fP configuration setting (or \fB--units\fP option directly
on command line) and \fBreport/suffix\fP
configuration setting (or \fB--nosuffix\fP command line option) to change this.

.nf
# lvs --units b --nosuffix
  LV    LSize   Cpy%Sync
  lvol1 4194304 100.00  
  lvol0 4194304    
.fi

If you want to configure whether report headings are displayed or not, use
\fBreport/headings\fP configuration settings (or \fB--noheadings\fP command
line option).

.nf
# lvs --noheadings
  lvol1 4.00m 100.00  
  lvol0 4.00m     
.fi

In some cases, it may be useful to display report content as key=value pairs
where key here is actually the field name. Use \fBreport/prefixes\fP
configuration setting (or \fB--nameprefixes\fP command line option) to switch
between standard output and the key=value output. The key=value pair is the
output that is suitable for use in scripts and for other tools to parse easily.
Usually, you also don't want to display headings with the output that has these
key=value pairs.

.nf
# lvs --noheadings --nameprefixes
  LVM2_LV_NAME='lvol1' LVM2_LV_SIZE='4.00m' LVM2_COPY_PERCENT='100.00'
  LVM2_LV_NAME='lvol0' LVM2_LV_SIZE='4.00m' LVM2_COPY_PERCENT=''
.fi

To define whether quotation marks in key=value pairs should be used or not,
use \fBreport/quoted\fP configuration setting (or \fB--unquoted\fP command
line option).

.nf
# lvs --noheadings --nameprefixes --unquoted
  LVM2_LV_NAME=lvol1 LVM2_LV_SIZE=4.00m LVM2_COPY_PERCENT=100.00
  LVM2_LV_NAME=lvol0 LVM2_LV_SIZE=4.00m LVM2_COPY_PERCENT=
.fi

For easier parsing, you can even transpose the report so each column now
becomes a row in the output. This is done with \fBreport/output_as_rows\fP
configuration setting (or \fB--rows\fP command line option).

.nf
# lvs --noheadings --nameprefixes --unquoted --rows
  LVM2_LV_NAME=lvol1 LVM2_LV_NAME=lvol0
  LVM2_LV_SIZE=4.00m LVM2_LV_SIZE=4.00m
  LVM2_COPY_PERCENT=100.00 LVM2_COPY_PERCENT=
.fi

Use \fBreport/separator\fP configuration setting (or \fB--separator\fP command
line option) to define your own field separator to use.

.nf
# lvs --noheadings --nameprefixes --unquoted --separator " | "
  LVM2_LV_NAME=lvol1 | LVM2_LV_SIZE=4.00m | LVM2_COPY_PERCENT=100.00
  LVM2_LV_NAME=lvol0 | LVM2_LV_SIZE=4.00m | LVM2_COPY_PERCENT=
.fi

If you are using your own separator, the columns in the output are not aligned
by default. Use \fBreport/aligned\fP configuration setting (or \fB--aligned\fP
command line option) for LVM to add extra spaces in report to align the output
properly.

.nf
# lvs --separator " | "
  LV | LSize | Cpy%Sync
  lvol1 | 4.00m | 100.00
  lvol0 | 4.00m | 

# lvs --separator " | " --aligned
  LV    | LSize | Cpy%Sync
  lvol1 | 4.00m | 100.00  
  lvol0 | 4.00m |         
.fi

Let's display one one more field in addition ("lv_tags" in this example)
for the lvs report output.

.nf
# lvs -o+lv_tags
  LV    LSize Cpy%Sync LV Tags  
  lvol1 4.00m 100.00            
  lvol0 4.00m          tagA,tagB
.fi

The "LV Tags" column in the example above displays two list values,
separated by "," character for LV lvol0. If you need different list item
separator, use \fBreport/list_item_separator\fP configuration setting its
definition.

.nf
# lvmconfig --type full report/list_item_separator
list_item_separator=";"

# lvs -o+tags
  LV    LSize Cpy%Sync LV Tags  
  lvol1 4.00m 100.00            
  lvol0 4.00m          tagA;tagB
.fi

But let's still use the original "," character for list_item_separator
for subsequent examples.

Format for any of time values displayed in reports can be configured with
\fBreport/time_format\fP configuretion setting. By default complete date
and time is displayed, including timezone.

.nf
# lvmconfig --type full report/time_format
time_format="%Y-%m-%d %T %z"

# lvs -o+time
  LV    LSize Cpy%Sync CTime                     
  lvol1 4.00m 100.00   2016-08-29 12:53:36 +0200 
  lvol0 4.00m          2016-08-29 10:15:17 +0200 
.fi

We can change time format in similar way as we do when using \fBdate\fP(1)
command or \fBstrftime\fP(3) function
(\fBlvmconfig --type default --withcomments report/time_format\fP will
give you complete list of available formatting options). In the example
below, we decided to use %s for number of seconds since Epoch (1970-01-01 UTC).

.nf
# lvmconfig --type full report/time_format
time_format="%s"

# lvs
  LV    Attr       LSize Cpy%Sync LV Tags   CTime                     
  lvol1 rwi-a-r--- 4.00m 100.00             1472468016                
  lvol0 -wi-a----- 4.00m          tagA,tagB 1472458517     
.fi

The \fBlvs\fP does not display hidden LVs by default - to include these LVs
in the output, you need to use \fB-a|--all\fP command line option. Names for
these hidden LVs are displayed within square brackets.

.nf
# lvs -a
  LV               LSize Cpy%Sync
  lvol1            4.00m 100.00  
  [lvol1_rimage_0] 4.00m         
  [lvol1_rmeta_0]  4.00m         
  [lvol1_rimage_1] 4.00m         
  [lvol1_rmeta_1]  4.00m         
  lvol0            4.00m      
.fi

You can configure LVM to display the square brackets for hidden LVs or not with
\fBreport/mark_hidden_devices\fP configuration setting.

.nf
# lvmconfig --type full report/mark_hidden_devices
mark_hidden_devices=0

# lvs -a
  LV             LSize Cpy%Sync
  lvol1          4.00m 100.00  
  lvol1_rimage_0 4.00m         
  lvol1_rmeta_0  4.00m         
  lvol1_rimage_1 4.00m         
  lvol1_rmeta_1  4.00m         
  lvol0          4.00m     
.fi

It's not recommended to use LV marks for hidden devices to decide whether the
LV is the one to use by end users or not. Please, use "lv_role" field instead
which can report whether the LV is "public" or "private". The private LVs are
used by LVM only and they should not be accessed directly by end users.

.nf
# lvs -a -o+lv_role
  LV             LSize Cpy%Sync Role                 
  lvol1          4.00m 100.00   public               
  lvol1_rimage_0 4.00m          private,raid,image   
  lvol1_rmeta_0  4.00m          private,raid,metadata
  lvol1_rimage_1 4.00m          private,raid,image   
  lvol1_rmeta_1  4.00m          private,raid,metadata
  lvol0          4.00m          public     
.fi

Some of the reporting fields that LVM reports are of binary nature. For such
fields, it's either  possible to display word representation of the value
(this is used by default) or numeric value (0/1 or -1 in case the value is
undefined).

.nf
# lvs -o+lv_active_locally
  LV    LSize Cpy%Sync ActLocal      
  lvol1 4.00m 100.00   active locally
  lvol0 4.00m          active locally
.fi

We can change the way how these binary values are displayed with
\fBreport/binary_values_as_numeric\fP configuration setting.

.nf
# lvmconfig --type full report/binary_values_as_numeric
binary_values_as_numeric=1

# lvs -o+lv_active_locally
  LV    LSize Cpy%Sync ActLocal  
  lvol1 4.00m 100.00            1
  lvol0 4.00m                   1
.fi

.SS Changing output format

LVM can output reports in different formats - use \fBreport/output_format\fP
configuration setting (or \fB--reportformat\fP command line option) to swith
the report output format. Currently, LVM supports \fB"basic"\fP (all the examples
we used above used this format) and \fB"JSON"\fP output format.

.nf
# lvs -o lv_name,lv_size --reportformat json
  {
      "report": [
          {
              "lv": [
                  {"lv_name":"lvol1", "lv_size":"4.00m"},
                  {"lv_name":"lvol0", "lv_size":"4.00m"}
              ]
          }
      ]
  }
.fi

Note that some configuration settings and command line options have no
effect with certain report formats. For example, with \fBJSON\fP output,
it doesn't have any meaning to use \fBreport/aligned\fP (\fB--aligned\fP),
\fBreport/noheadings\fP (\fB--noheadings\fP), \fBreport/columns_as_rows\fP
(\fB--rows\fP) or \fBreport/buffered\fP (\fB--unbuffered\fP). All these
configuration settings and command line options are ignored if using the
\fBJSON\fP report output format.

.SS Selection

If you need to select only specific rows from report, you can use LVM's
report selection feature. If you call \fB<lvm_command> -S help\fP, you'll get
quick help on selection. The help contains list of all fields that LVM
can use in reports together with its type enclosed in square brackets.
The example below contains a line from lvs -S help.

.nf
# lvs -S help
    ...
    lv_size                - Size of LV in current units. [size]
    ...
.fi

This line tells you you that the "lv_size" field is of "size" type. If you
look at the bottom of the help output, you can see section about
"Selection operators" and its "Comparison operators".

.nf
# lvs -S help
 ...
Selection operators
-------------------
Comparison operators:
   =~  - Matching regular expression. [regex]
   !~  - Not matching regular expression. [regex]
    =  - Equal to. [number, size, percent, string, string list, time]
   !=  - Not equal to. [number, size, percent, string, string_list, time]
   >=  - Greater than or equal to. [number, size, percent, time]
    >  - Greater than. [number, size, percent, time]
   <=  - Less than or equal to. [number, size, percent, time]
    <  - Less than. [number, size, percent, time]
since  - Since specified time (same as '>='). [time]
after  - After specified time (same as '>'). [time]
until  - Until specified time (same as '<='). [time]
before  - Before specified time (same as '<'). [time]
 ...
.fi

Here you can match comparison operators that you may use with the "lv_size"
field which is of type "size" - it's =, !=, >=, >, <= and <. You can find
applicable comparison operators for other fields and other field types the
same way.

To demostrate selection functionality in LVM, we will create more LVs in
addition to lvol0 and lvol1 we used in our previous examples.

.nf
# lvs -o name,size,origin,snap_percent,tags,time
  LV    LSize Origin Snap%  LV Tags        CTime                     
  lvol4 4.00m lvol2  24.61                 2016-09-09 16:57:44 +0200 
  lvol3 4.00m lvol2  5.08                  2016-09-09 16:56:48 +0200 
  lvol2 8.00m               tagA,tagC,tagD 2016-09-09 16:55:12 +0200 
  lvol1 4.00m                              2016-08-29 12:53:36 +0200 
  lvol0 4.00m               tagA,tagB      2016-08-29 10:15:17 +0200
.fi

When selecting size and percent fields, we don't need to use units.
For sizes, default "m" (for MiB) is used - this is the same behaviour
as already used for LVM commands when specifying sizes (e.g. lvcreate -L).
For percent fields, "%" is assumed automatically if it's not specified.
The example below also demonstrates how several criteria can be combined
together.

.nf
# lvs -o name,size,snap_percent -S 'size=8m'
  LV    LSize 
  lvol2 8.00m

# lvs -o name,size,snap_percent -S 'size=8'
  LV    LSize 
  lvol2 8.00m

# lvs -o name,size,snap_percent -S 'size < 5000k'
  LV    LSize Snap% 
  lvol4 4.00m 24.61 
  lvol3 4.00m 5.08  
  lvol1 4.00m       
  lvol0 4.00m 

# lvs -o name,size,snap_percent -S 'size < 5000k && snap_percent > 20'
  LV    LSize Snap% 
  lvol4 4.00m 24.61 

# lvs -o name,size,snap_percent \\
    -S '(size < 5000k && snap_percent > 20%) || name=lvol2'
  LV    LSize Snap% 
  lvol4 4.00m 24.61 
  lvol2 8.00m       
.fi

You can also use selection together with processing-oriented commands.

.nf
# lvchange --addtag test -S 'size < 5000k'
  Logical volume vg/lvol1 changed.
  Logical volume vg/lvol0 changed.
  Logical volume vg/lvol3 changed.
  Logical volume vg/lvol4 changed.

# lvchange --deltag test -S 'tags = test'
  Logical volume vg/lvol1 changed.
  Logical volume vg/lvol0 changed.
  Logical volume vg/lvol3 changed.
  Logical volume vg/lvol4 changed.
.fi

LVM can recognize more complex values used in selection criteria for
string list and time field types. For string lists, you can match
whole list strictly, its subset or intersection. Let's take "lv_tags"
field as an example - we select only rows which contain "tagA" within
tags field. We're using { } to denote that we're interested in subset
that matches. If the subset has only one item, we can leave out { }.

.nf
# lvs -o name,tags -S 'tags={tagA}'
  LV    LV Tags       
  lvol2 tagA,tagC,tagD
  lvol0 tagA,tagB   
  
# lvs -o name,tags -S 'tags=tagA'
  LV    LV Tags       
  lvol2 tagA,tagC,tagD
  lvol0 tagA,tagB   
.fi

Depending on whether we use "&&" (or ",") or "||" ( or "#") as delimiter
for items in the set we define in selection criterion for string list,
we either match subset ("&&" or ",") or even intersection ("||" or "#").

.nf
# lvs -o name,tags -S 'tags={tagA,tagC,tagD}'
  LV    LV Tags       
  lvol2 tagA,tagC,tagD

# lvs -o name,tags -S 'tags={tagA || tagC || tagD}'
  LV    LV Tags       
  lvol2 tagA,tagC,tagD
  lvol0 tagA,tagB     
.fi

To match the complete set, use [ ] with "&&" (or ",") as delimiter for items.
Also note that the order in which we define items in the set is not relevant.

.nf
# lvs -o name,tags -S 'tags=[tagA]'                

# lvs -o name,tags -S 'tags=[tagB,tagA]'
  LV    LV Tags  
  lvol0 tagA,tagB
.fi

If you use [ ] with "||" (or "#"), this is exactly the same as using { }.

.nf
# lvs -o name,tags -S 'tags=[tagA || tagC || tagD]'
  LV    LV Tags       
  lvol2 tagA,tagC,tagD
  lvol0 tagA,tagB  
.fi

To match a set with no items, use "" to denote this (note that we have
output compaction enabled so the "LV Tags" column is not displayed in
the example below because it's blank and so it gets compacted).

.nf
# lvs -o name,tags -S 'tags=""'
  LV    
  lvol4
  lvol3
  lvol1

# lvs -o name,tags -S 'tags!=""'
  LV    LV Tags       
  lvol2 tagA,tagC,tagD
  lvol0 tagA,tagB  
.fi

When doing selection based on time fields, we can use either standard,
absolute or freeform time expressions in selection criteria. Examples below
are using standard forms.

.nf
# lvs -o name,time
  LV    CTime                     
  lvol4 2016-09-09 16:57:44 +0200 
  lvol3 2016-09-09 16:56:48 +0200 
  lvol2 2016-09-09 16:55:12 +0200 
  lvol1 2016-08-29 12:53:36 +0200 
  lvol0 2016-08-29 10:15:17 +0200 

# lvs -o name,time -S 'time since "2016-09-01"'
  LV    CTime                     
  lvol4 2016-09-09 16:57:44 +0200 
  lvol3 2016-09-09 16:56:48 +0200 
  lvol2 2016-09-09 16:55:12 +0200 

# lvs -o name,time -S 'time since "2016-09-09 16:56"'
  LV    CTime                     
  lvol4 2016-09-09 16:57:44 +0200 
  lvol3 2016-09-09 16:56:48 +0200 

# lvs -o name,time -S 'time since "2016-09-09 16:57:30"'
  LV    CTime                     
  lvol4 2016-09-09 16:57:44 +0200 

# lvs -o name,time \\ 
    -S 'time since "2016-08-29" && time until "2016-09-09 16:55:12"'
  LV    CTime                     
  lvol2 2016-09-09 16:55:12 +0200 
  lvol1 2016-08-29 12:53:36 +0200 
  lvol0 2016-08-29 10:15:17 +0200 

# lvs -o name,time \\
    -S 'time since "2016-08-29" && time before "2016-09-09 16:55:12"'
  LV    CTime                     
  lvol1 2016-08-29 12:53:36 +0200 
  lvol0 2016-08-29 10:15:17 +0200 
.fi

Time operators have synonyms: ">=" for since, "<=" for until,
">" for "after" and "<" for "before".

.nf
# lvs -o name,time \\
    -S 'time >= "2016-08-29" && time <= "2016-09-09 16:55:30"'
  LV    CTime                     
  lvol2 2016-09-09 16:55:12 +0200 
  lvol1 2016-08-29 12:53:36 +0200 
  lvol0 2016-08-29 10:15:17 +0200 

# lvs -o name,time \\
    -S 'time since "2016-08-29" && time < "2016-09-09 16:55:12"'
  LV    CTime                     
  lvol1 2016-08-29 12:53:36 +0200 
  lvol0 2016-08-29 10:15:17 +0200 
.fi

Example below demonstrates using absolute time expression.

.nf
# lvs -o name,time --config report/time_format="%s"
  LV    CTime                     
  lvol4 1473433064                
  lvol3 1473433008                
  lvol2 1473432912                
  lvol1 1472468016                
  lvol0 1472458517  

# lvs -o name,time -S 'time since @1473433008'
  LV    CTime                     
  lvol4 2016-09-09 16:57:44 +0200 
  lvol3 2016-09-09 16:56:48 +0200 
.fi

Examples below demonstrates using freeform time expressions.

.nf
# lvs -o name,time -S 'time since "2 weeks ago"'
  LV    CTime                     
  lvol4 2016-09-09 16:57:44 +0200 
  lvol3 2016-09-09 16:56:48 +0200 
  lvol2 2016-09-09 16:55:12 +0200 
  lvol1 2016-08-29 12:53:36 +0200 
  lvol0 2016-08-29 10:15:17 +0200 

# lvs -o name,time -S 'time since "1 week ago"'
  LV    CTime                     
  lvol4 2016-09-09 16:57:44 +0200 
  lvol3 2016-09-09 16:56:48 +0200 
  lvol2 2016-09-09 16:55:12 +0200 

# lvs -o name,time -S 'time since "2 weeks ago"'
  LV    CTime                     
  lvol1 2016-08-29 12:53:36 +0200 
  lvol0 2016-08-29 10:15:17 +0200 

# lvs -o name,time -S 'time before "1 week ago"'
  LV    CTime                     
  lvol1 2016-08-29 12:53:36 +0200 
  lvol0 2016-08-29 10:15:17 +0200 

# lvs -o name,time -S 'time since "68 hours ago"'
  LV    CTime                     
  lvol4 2016-09-09 16:57:44 +0200 
  lvol3 2016-09-09 16:56:48 +0200 
  lvol2 2016-09-09 16:55:12 +0200 

# lvs -o name,time -S 'time since "1 year 3 months ago"'
  LV    CTime                     
  lvol4 2016-09-09 16:57:44 +0200 
  lvol3 2016-09-09 16:56:48 +0200 
  lvol2 2016-09-09 16:55:12 +0200 
  lvol1 2016-08-29 12:53:36 +0200 
  lvol0 2016-08-29 10:15:17 +0200 
.fi

.SS Command log reporting

As described in \fBcategorization based on reporting facility\fP section
at the beginning of this document, both \fBreport-oriented\fP and
\fBprocessing-oriented\fP LVM commands can report the command log if
this is enabled with \fBlog/report_command_log\fP configuration setting.
Just like any other report, we can set the set of fields to display
(\fBlog/command_log_cols\fP) and to sort by (\fBlog/command_log_sort\fP)
for this report.

.nf
# lvmconfig --type full log/report_command_log log/command_log_cols \\
   log/command_log_sort log/command_log_selection
report_command_log=1
command_log_cols="log_seq_num,log_type,log_context,log_object_type,
                  log_object_name,log_object_group,log_message,
                  log_errno,log_ret_code"
command_log_sort="log_seq_num"
command_log_selection="!(log_type=status && message=success)"


# lvs
  Logical Volume
  ==============
  LV    LSize Cpy%Sync
  lvol1 4.00m 100.00  
  lvol0 4.00m         
  
  Command Log
  ===========
  Seq LogType Context ObjType ObjName ObjGrp  Msg     Errno RetCode
.fi

As you can see, the command log is empty (it contains only field names).
By default, LVM uses selection on the command log report and this case
no row matched the selection criteria, see also \fBlog report specifics\fP
section in this document for more information. We're displaying complete
log report in the example below where we can see that both LVs lvol0 and
lvol1 were successfully processed as well as the VG vg they are part of.

.nf
# lvmconfig --type full log/command_log_selection
command_log_selection="all"

# lvs
  Logical Volume
  ==============
  LV    LSize Cpy%Sync
  lvol1 4.00m 100.00  
  lvol0 4.00m         
  
  Command Log
  ===========
  Seq LogType Context    ObjType ObjName ObjGrp  Msg     Errno RetCode
    1 status  processing lv      lvol0   vg      success     0       1
    2 status  processing lv      lvol1   vg      success     0       1
    3 status  processing vg      vg              success     0       1

# lvchange -an vg/lvol1
  Command Log
  ===========
  Seq LogType Context    ObjType ObjName ObjGrp  Msg     Errno RetCode
    1 status  processing lv      lvol1   vg      success     0       1
    2 status  processing vg      vg              success     0       1
.fi

.SS Handling multiple reports per single command

To configure the log report directly on command line, we need to use
\fB--configreport\fP option before we start any \fB-o|--options\fP,
\fB-O|--sort\fP or \fB-S|--select\fP that is targeted for log report.

.nf
# lvs -o lv_name,lv_size --configreport log -o log_object_type, \\
   log_object_name,log_message,log_ret_code
  Logical Volume
  ==============
  LV    LSize
  lvol1 4.00m
  lvol0 4.00m
  
  Command Log
  ===========
  ObjType ObjName Msg     RetCode
  lv      lvol0   success       1
  lv      lvol1   success       1
  vg      vg      success       1
.fi

The \fBlvm fullreport\fP, with or without log report, consists of several
reports - the \fB--configreport\fP is also used to target particular
subreport here.

Below is an extended example with \fBlvm fullreport\fP to illustrate
combination of various options. The report output is in JSON format.
Also, we configure "vg", "pvseg", "seg" and "log" subreport to contain
only specified fields. For the "pvseg" subreport, we're intested only
in PV names having "sda" in their name. For the "log" subreport we're
intested only in log lines related to either "lvol0" object or object
having "sda" in its name. Also, for the log subreport we define ordering
to be based on "log_object_type" field.

.nf
# lvm fullreport --reportformat json \\
   --configreport vg -o vg_name,vg_size \\
   --configreport pvseg -o pv_name,pvseg_start \\
                        -S 'pv_name=~sda' \\
   --configreport seg -o lv_name,seg_start \\
   --configreport log -o log_object_type,log_object_name \\
                      -O log_object_type \\
                      -S 'log_object_name=lvol0 || \\
                          log_object_name=~sda'
  {
      "report": [
          {
              "vg": [
                  {"vg_name":"vg", "vg_size":"200.00m"}
              ]
              ,
              "pv": [
                  {"pv_name":"/dev/sda", "vg_name":"vg"},
                  {"pv_name":"/dev/sdb", "vg_name":"vg"}
              ]
              ,
              "lv": [
                  {"lv_name":"lvol0", "vg_name":"vg"},
                  {"lv_name":"lvol1", "vg_name":"vg"}
              ]
              ,
              "pvseg": [
                  {"pv_name":"/dev/sda", "pvseg_start":"0"},
                  {"pv_name":"/dev/sda", "pvseg_start":"1"},
                  {"pv_name":"/dev/sda", "pvseg_start":"2"},
                  {"pv_name":"/dev/sda", "pvseg_start":"3"}
              ]
              ,
              "seg": [
                  {"lv_name":"lvol0", "seg_start":"0 "},
                  {"lv_name":"lvol1", "seg_start":"0 "}
              ]
          }
      ]
      ,
      "log": [
          {"log_object_type":"lv", "log_object_name":"lvol0"},
          {"log_object_type":"lv", "log_object_name":"lvol0"},
          {"log_object_type":"pv", "log_object_name":"/dev/sda"},
          {"log_object_type":"pv", "log_object_name":"/dev/sda"},
      ]
  }
.fi

.SS Report extensions for LVM shell

As already stated in \fBlog report coverage\fP paragraph under
\fBlog report specifics\fP in this documentation, when using \fBLVM shell\fP
the \fBlog report\fP coverage is wider. There's also special command
designed to query last command's log report in the \fBLVM shell\fP -
the \fBlastlog\fP command.

The example below illustrates a situation where we called lvs command.
After that, we inspected the log report with the \fBlastlog\fP, without
any selection so all the log report is displayed on output. Then we called
\fBlastlog\fP further, giving various selection criteria. Then we ran
unknown LVM command "abc" for which the log report displays appropriate
failure state.

.nf
# lvm
lvm> lvs
  Logical Volume
  ==============
  LV    LSize Cpy%Sync
  lvol1 4.00m 100.00  
  lvol0 4.00m         
  
  Command Log
  ===========
  Seq LogType Context    ObjType ObjName ObjGrp  Msg     Errno RetCode
    1 status  processing lv      lvol0   vg      success     0       1
    2 status  processing lv      lvol1   vg      success     0       1
    3 status  processing vg      vg              success     0       1
    4 status  shell      cmd     lvs             success     0       1

lvm> lastlog    
  Command Log
  ===========
  Seq LogType Context    ObjType ObjName ObjGrp  Msg     Errno RetCode
    1 status  processing lv      lvol0   vg      success     0       1
    2 status  processing lv      lvol1   vg      success     0       1
    3 status  processing vg      vg              success     0       1
    4 status  shell      cmd     lvs             success     0       1

lvm> lastlog -S log_object_type=lv
  Command Log
  ===========
  Seq LogType Context    ObjType ObjName ObjGrp  Msg     Errno RetCode
    1 status  processing lv      lvol0   vg      success     0       1
    2 status  processing lv      lvol1   vg      success     0       1

lvm> lastlog -S log_context=shell
  Command Log
  ===========
  Seq LogType Context ObjType ObjName ObjGrp  Msg     Errno RetCode
    4 status  shell   cmd     lvs             success     0       1

lvm> abc
  Command Log
  ===========
  Seq LogType Context ObjType ObjName ObjGrp  Msg                                 Errno RetCode
    1 error   shell   cmd     abc             No such command 'abc'.  Try 'help'.    -1       0
    2 status  shell   cmd     abc             failure                                -1       2
.fi

.SH SEE ALSO
\fBlvm\fP (8),
\fBlvmconfig\fP (8),
\fBlvm fullreport\fP (8)