LVMREPORT(7)LVMREPORT(7)NAMElvmreport — LVM reporting and related features
DESCRIPTION
LVM uses single reporting infrastructure that sets standard on LVM com‐
mand's output and it provides wide range of configuration settings and
command line options to customize report and filter the report's out‐
put.
Categorization based on reporting facility
Based on functionality, commands which make use of the reporting infra‐
structure are divided in two groups:
Report-oriented
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 main report. The set
of report-only commands include: pvs, vgs, lvs, pvdisplay,
vgdisplay, lvdisplay, lvm devtypes, lvm fullreport. For further
information about main report, see main report specifics.
Processing-oriented
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.
If enabled, so called log report is either displayed solely (for processing-
oriented commands) or in addition to main report (for report-oriented com‐
mands). The log report contains a log of operations, messages and per-object
status with complete object identification collected during LVM command execu‐
tion. See log report specifics for more information about this report type.Terms
When describing reporting functionality and features in this text, we
will use terms row and column. 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 col‐
umn headings which are short descriptions for the columns. The columns
are referenced by column names. Please note that this text is also
using term field interchangeably with the term column. Most of the time
the term columns is abbreviated as col in configuration.
Common report configuration settings and command line options
There are common configuration settings and command line options which
apply to both main report and log report. Following lists contain all
of them, separated into groups based on their use.
Common configuration settings:
· Changing report output format, composition and other
output modifiers:
- 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
· Special settings
- report/buffered
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 lvmconfig --type default --withcomments <setting>.
There are more configuration settings in addition to the common set
listed above, but they are specific to either main report or log
report, see main report specifics and log report specifics 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.
Common command line options:
· Definition of the set set of fields to use
- --options|-o FieldSet
Field set to use. See main report specifics and log
report specifics for information about field sets
configured with global configuratin settings that
this option overrides.
- --options|-o+ FieldSet
Fields to include to current field set. See main
report specifics and log report specifics for
information about field sets configured with global
configuration settings that this option extends.
- --options|-o- FieldSet
Fields to exclude from current field set. See main
report specifics and log report specifics for
information about field sets configured with global
configuration settings that this option reduces.
- --options|-o# FieldSet
Compaction of unused fields. Overrides report/com‐
pact_output_cols configuration setting.
· Sorting
- --sort|-O+ FieldSet
Fields to sort by in ascending order. See main
report specifics and log report specifics for
information about field sets configured with global
configuration settings that this option overrides.
- --sort|-O- FieldSet
Fields to sort by in descending order. See main
report specifics and log report specifics for
information about fields sets configured with
global configuration settings that this options
overrides.
· Selection
- --select|-S Selection
Define selection criteria for report output. For
log report, this also overrides log/com‐
mand_log_selection configuration setting, see also
log report specifics.
· Changing output format and composition
- --reportformat
Overrides report/output_format configuration set‐
ting.
- --aligned
Overrides report/aligned configuration setting.
- --binary
Overrides report/binary_values_as_numeric configu‐
ration setting.
- --nameprefixes
Overrides report/prefixes configuration setting.
- --noheadings
Overrides report/noheadings configuration setting.
- --nosuffix
Overrides global/suffix configuration setting.
- --rows
Overrides report/columns_as_rows configuration set‐
ting.
- --separator
Overrides report/separator configuration setting.
- --units
Overrides global/units configuration setting.
- --unquoted
Overrides report/quoted configuration setting.
· Special options
- --configreport ReportName
This defines the ReportName for which any subse‐
quent -o--columns, -O--sort or -S--select applies
to. See also main report specifics and log report
specifics for possible ReportName values.
- --logonly
When an LVM command contains both main report and
log report, this option suppresses the main report
output and it causes the log report output to be
displayed only.
- --unbuffered
Overrides report/bufffered configuration setting.
The FieldSet 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 Selection is a string with selection criteria, see
also Selection paragraph below for more information about constructing
these criteria.
Main report specifics
The main report currently encompasses these distinct subtypes, refer‐
enced by their name - ReportName as listed below. The command in paren‐
thesis 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 ReportName):
· pv representing report about Physical Volumes (pvs)
- report/pvs_cols
- report/pvs_sort
· pvseg representing report about Physical Volume Segments (pvs
--segments)
- report/pvseg_cols
- report/pvseg_sort
· vg representing report about Volume Groups (vgs)
- report/vgs_cols
- report/vgs_sort
· lv representing report about Logical Volumes (lvs)
- report/lvs_cols
- report/lvs_sort
· seg representing report about Logical Volume Segments (lvs
--segments)
- report/segs_cols
- report/segs_sort
· full representing report combining all of the above as a
whole (lvm fullreport)
- report/pvs_cols_full
- report/pvs_sort_full
- report/pvsegs_cols_full
- report/pvseg_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
· devtype representing report about device types (lvm devtypes)
- report/devtypes_cols
- report/devtypes_sort
Use pvs, vgs, lvs -o help or lvm devtypes -o help 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 full, it's not necessary to use
--configreport ReportName to denote which report any subsequent -o, -O
or -S option applies to as they always apply to the single main report
type. Currently, lvm fullreport is the only command that includes more
than one main report subtype. Therefore, the --configreport is particu‐
larly suitable for the full report if you need to configure each of its
subreports in a different way.
Log report specifics
You can enable log report with log/report_command_log configuration
setting - this functionality is disabled by default. The log report
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:
· log representing log report
- log/command_log_cols
- log/command_log_sort
- log/command_log_selection
You always need to use --configreport log together with -o--options,
-O--sort or -S--selection to override configuration settings directly
on command line for log report. When compared to main report, in addi‐
tion to usual configuration settings for report fields and sorting, the
log report has also configuration option for selection - report/com‐
mand_log_selection. This configuration setting is provided for conve‐
nience so it's not necessary to use -S--select on command line each
time an LVM command is executed and we need the same selection criteria
to be applied for log report. Default selection criteria used for log
report are log/command_log_selection="!(log_type=status && message=suc‐
cess)". This means that, by default, log report 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 log report content below).
Log report coverage
Currently, when running LVM commands directly (not in LVM shell), the
log report covers command's processing stage 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 log report. By default, that is
standard error output for error and warning messages and standard out‐
put for common print-like messages.
When running LVM commands in LVM shell, the log report covers the whole
LVM command's execution, including command's processing as well as ini‐
tialization and finalization stage. 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 LVM shell needs to prepare log report
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 log report and display
messages on output directly.
For these reasons and for completeness, it's not possible to rely fully
on log report 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 custom file descriptor that you prepare before running an LVM
command or LVM shell and then you make LVM to use these file descrip‐
tors for different kinds of output by defining environment variables
with file descriptor numbers. See also LVM_OUT_FD, LVM_ERR_FD and
LVM_REPORT_FD environment variable description in lvm(8) man page.
Also note that, by default, reports use the same file descriptor as
common print-like messages, which is standard output. If you plan to
use log report in your scripts or any external tool, you should use
LVM_OUT_FD, LVM_ERR_FD and LVM_REPORT_FD to separate all output types
to different file descriptors. For example, with bash, that would be:
LVM_OUT_FD=3 LVM_ERR_FD=4 LVM_REPORT_FD=5 <lvm command>
3>out_file 4>err_file 5>report_file
Where the <lvm_command> is either direct LVM command or LVM shell. You
can collect all three types of output in particular files then.
Log report content
Each item in the log report consists of these set of fields providing
various information:
· Basic information (mandatory):
- log_seq_num
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.
- log_type
Type of log for the item. Currently, these types are used:
status for any status information that is logged
print for any common message printed while the log
is collected
error for any error message printed while the log
is collected
warn for any warning message printed while the log
is collected
- log_context
Context of the log for the item. Currently, two contexts
are identified:
shell for the log collected in the outermost code
before and after executing concrete LVM commands
processing for the log collected while processing
LVM entities during LVM command execution
· Message (mandatory):
- log_message
Any message associated with current item. For status log
type, the message contains either success or failure
denoting current state. For print, error and warn log
types, the message contains the exact message of that type
that got issued.
· Object information (used only if applicable):
- log_object_type field
Type of the object processed. Currently, these object
types are recognized:
cmd for command as a whole
orphan for processing group of PVs not in any VG
yet
pv for PV processing
label for direct PV label processing (without VG
metadata)
vg for VG processing
lv for LV processing
- log_object_name
Name of the object processed.
- log_object_id
ID of the object processed.
- log_object_group
A group where the processed object belongs to.
- log_object_group_id
An ID of a group where the processed object belongs to.
· Numeric status (used only if applicable)
- log_errno
Error number associated with current item.
- log_ret_code
Rreturn code associated with current item.
You can also run <lvm_command> --configreport log -o help to to display
complete list of fields that you may use for the log report.
Selection
Selection is used for a report to display only rows that match selec‐
tion criteria. All rows are displayed with the additional selected
field (-o selected) displaying 1 if the row matches the Selection and 0
otherwise. The selection criteria are a set of statements combined by
logical and grouping operators. The statement consists of a field name
for which a set of valid values is defined using comparison operators.
For complete list of fields names that you can use in selection, see
the output of <lvm_command> -S help. The help output also contains type
of values that each field displays enclosed in brackets.
List of operators recognized in selection criteria
· Comparison operators (cmp_op)
=~ matching regular expression.
!~ not matching regular expression.
= equal to.
!= not equal to.
>= greater than or equal to.
> greater than
<= less than or equal to.
< less than.
· Binary logical operators (cmp_log)
&& all fields must match
, all fields must match
|| at least one field must match
# at least one field must match
· Unary logical operators
! logical negation
· Grouping operators
( left parenthesis
) right parenthesis
[ list start
] list end
{ list subset start
} list subset end
Field types and selection operands
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 <lvm command> -S help where you can find the
type name enclosed in square brackets. Currently, LVM recognizes these
field types in reports:
· string 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)
· string list for set of strings
· number for integer value
· size for integer or floating point number with size unit suf‐
fix (see also lvcreate(8) man page and description for
"-L--size" option for the list of recognized suffixes)
· percent for floating point number with or without "%" suffix
(e.g. 50 or 50%)
· time for time values
When using string list 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.
· matching the set strictly where all items must match - use [
], e.g. ["a","b","c"]
· matching a subset of the set - use { } with "," or "&&" as
item delimiter, e.g. {"a","b","c"}
· matching an intersection with the set - use { } with "#" or
"||" as item delimiter, e.g. {"a" || "b" || "c"}
When using time 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
EXAMPLES section.
· Standard time format
- date
YYYY-MM-DD
YYYY-MM, auto DD=1
YYYY, auto MM=01 and DD=01
- time
hh:mm:ss
hh:mm, auto ss=0
hh, auto mm=0, auto ss=0
- timezone
+hh:mm or -hh:mm
+hh or -hh
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 auto‐
matically with second granularity. For example:
"2015-07-07 9:51" means range of "2015-07-07
9:51:00" - "2015-07-07 9:51:59".
"2015-07" means range of "2015-07-01 0:00:00" -
"2015-07-31 23:59:59"
"2015" means range of "2015-01-01 0:00:00" -
"2015-12-31 23:59:59"
· Absolute time format
Absolute time is defined as number of seconds since the Epoch
(1970:01:01 00:00 +00:00).
- @seconds
· Freeform time format
- weekday names ("Sunday" - "Saturday" or abbreviated as
"Sun" - "Sat")
- labels for points in time ("noon", "midnight")
- labels for a day relative to current day ("today", "yes‐
terday")
- points back in time with relative offset from today (N is
a number)
"N" "seconds" / "minutes" / "hours" / "days" /
"weeks" / "years" "ago"
"N" "secs" / "mins" / "hrs" ... "ago"
"N" "s" / "m" / "h" ... "ago"
- time specification either in hh:mm:ss format or with AM/PM
suffixes
- month names ("January" - "December" or abbreviated as
"Jan" - "Dec")
Informal grammar specification
STATEMENT = column cmp_op VALUE | STATEMENT log_op STATE‐
MENT | (STATEMENT) | !(STATEMENT)
VALUE = [VALUE log_op VALUE]
For list-based types: string list. Matches strictly. The
log_op must always be of one type within the whole list
value.
VALUE = {VALUE log_op VALUE}
For list-based types: string list. Matches a subset. The
log_op must always be of one type within the whole list
value.
VALUE = value
For scalar types: number, size, percent, string (or
string regex).
EXAMPLES
Basic usage
We start our examples with default configuration - lvmconfig(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.
# 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
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 pvs(8), vgs(8),
lvs(8) man pages for more information. The field set for each report
type is configured with configuration settings as we already mentioned
in main report specifics section in this man page.
# 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"
# 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
We will use report/lvs_cols and report/lvs_sort configuration settings
to define our own list of fields to use and to sort by that is differ‐
ent from defaults. You can do this for other reports in same manner
with report/{pvs,pvseg,vgs,seg}_{cols,sort} 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.
# 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
You can use -o--options command line option to override current config‐
uration directly on command line.
# 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
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 lvm-fullre‐
port(8) man page for more information. The fullreport has its own con‐
figuration 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.
# 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"
# 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
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 report/compact_output=1 in your configuration.
# 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
Alternatively, you can define which fields should be compacted by con‐
figuring report/compact_output_cols configuration setting (or
-o--options # command line option).
# 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
We will use report/compact_output=1 for subsequent examples.
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 report/units configuration setting (or --units option directly on
command line) and report/suffix configuration setting (or --nosuffix
command line option) to change this.
# lvs --units b --nosuffix
LV LSize Cpy%Sync
lvol1 4194304 100.00
lvol0 4194304
If you want to configure whether report headings are displayed or not,
use report/headings configuration settings (or --noheadings command
line option).
# lvs --noheadings
lvol1 4.00m 100.00
lvol0 4.00m
In some cases, it may be useful to display report content as key=value
pairs where key here is actually the field name. Use report/prefixes
configuration setting (or --nameprefixes 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.
# 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=''
To define whether quotation marks in key=value pairs should be used or
not, use report/quoted configuration setting (or --unquoted command
line option).
# 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=
For easier parsing, you can even transpose the report so each column
now becomes a row in the output. This is done with report/out‐
put_as_rows configuration setting (or --rows command line option).
# 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=
Use report/separator configuration setting (or --separator command line
option) to define your own field separator to use.
# 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=
If you are using your own separator, the columns in the output are not
aligned by default. Use report/aligned configuration setting (or
--aligned command line option) for LVM to add extra spaces in report to
align the output properly.
# 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 |
Let's display one one more field in addition ("lv_tags" in this exam‐
ple) for the lvs report output.
# lvs -o+lv_tags
LV LSize Cpy%Sync LV Tags
lvol1 4.00m 100.00
lvol0 4.00m tagA,tagB
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 report/list_item_separator configuration setting
its definition.
# 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
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 report/time_format configuretion setting. By default complete date
and time is displayed, including timezone.
# 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
We can change time format in similar way as we do when using date(1)
command or strftime(3) function (lvmconfig --type default --withcom‐
ments report/time_format will give you complete list of available for‐
matting options). In the example below, we decided to use %s for number
of seconds since Epoch (1970-01-01 UTC).
# 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
The lvs does not display hidden LVs by default - to include these LVs
in the output, you need to use -a--all command line option. Names for
these hidden LVs are displayed within square brackets.
# 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
You can configure LVM to display the square brackets for hidden LVs or
not with report/mark_hidden_devices configuration setting.
# 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
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.
# 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
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).
# lvs -o+lv_active_locally
LV LSize Cpy%Sync ActLocal
lvol1 4.00m 100.00 active locally
lvol0 4.00m active locally
We can change the way how these binary values are displayed with
report/binary_values_as_numeric configuration setting.
# 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
Changing output format
LVM can output reports in different formats - use report/output_format
configuration setting (or --reportformat command line option) to swith
the report output format. Currently, LVM supports "basic" (all the
examples we used above used this format) and "JSON" output format.
# lvs -o lv_name,lv_size --reportformat json
{
"report": [
{
"lv": [
{"lv_name":"lvol1", "lv_size":"4.00m"},
{"lv_name":"lvol0", "lv_size":"4.00m"}
]
}
]
}
Note that some configuration settings and command line options have no
effect with certain report formats. For example, with JSON output, it
doesn't have any meaning to use report/aligned (--aligned),
report/noheadings (--noheadings), report/columns_as_rows (--rows) or
report/buffered (--unbuffered). All these configuration settings and
command line options are ignored if using the JSON report output for‐
mat.
Selection
If you need to select only specific rows from report, you can use LVM's
report selection feature. If you call <lvm_command> -S help, 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.
# lvs -S help
...
lv_size - Size of LV in current units. [size]
...
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".
# 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]
...
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.
# 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
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.
# 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
You can also use selection together with processing-oriented commands.
# 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.
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 { }.
# 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
Depending on whether we use "&&" (or ",") or "||" ( or "#") as delim‐
iter for items in the set we define in selection criterion for string
list, we either match subset ("&&" or ",") or even intersection ("||"
or "#").
# 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
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.
# lvs -o name,tags -S 'tags=[tagA]'
# lvs -o name,tags -S 'tags=[tagB,tagA]'
LV LV Tags
lvol0 tagA,tagB
If you use [ ] with "||" (or "#"), this is exactly the same as using {
}.
# lvs -o name,tags -S 'tags=[tagA || tagC || tagD]'
LV LV Tags
lvol2 tagA,tagC,tagD
lvol0 tagA,tagB
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).
# 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
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.
# 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
Time operators have synonyms: ">=" for since, "<=" for until, ">" for
"after" and "<" for "before".
# 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
Example below demonstrates using absolute time expression.
# 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
Examples below demonstrates using freeform time expressions.
# 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
Command log reporting
As described in categorization based on reporting facility section at
the beginning of this document, both report-oriented and processing-
oriented LVM commands can report the command log if this is enabled
with log/report_command_log configuration setting. Just like any other
report, we can set the set of fields to display (log/command_log_cols)
and to sort by (log/command_log_sort) for this report.
# 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
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 log report
specifics section in this document for more information. We're display‐
ing 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.
# 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
Handling multiple reports per single command
To configure the log report directly on command line, we need to use
--configreport option before we start any -o--options, -O--sort or
-S--select that is targeted for log report.
# 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
The lvm fullreport, with or without log report, consists of several
reports - the --configreport is also used to target particular subre‐
port here.
Below is an extended example with lvm fullreport to illustrate combina‐
tion 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 order‐
ing to be based on "log_object_type" field.
# 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"},
]
}
Report extensions for LVM shell
As already stated in log report coverage paragraph under log report
specifics in this documentation, when using LVM shell the log report
coverage is wider. There's also special command designed to query last
command's log report in the LVM shell - the lastlog command.
The example below illustrates a situation where we called lvs command.
After that, we inspected the log report with the lastlog, without any
selection so all the log report is displayed on output. Then we called
lastlog further, giving various selection criteria. Then we ran unknown
LVM command "abc" for which the log report displays appropriate failure
state.
# 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
SEE ALSO
lvm (8), lvmconfig (8), lvm fullreport (8)
Red Hat, Inc LVM TOOLS 2.02.176(2) (2017-11-03) LVMREPORT(7)
