plucky (7) lvmreport.7.gz

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NAME

       lvmreport — LVM reporting and related features

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.

USAGE

   Categorization based on reporting facility
       Based  on  functionality,  commands  which  make  use  of the reporting infrastructure are divided in two
       groups:

       Report-oriented commands
              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 commands
              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 commands). The log report contains a log of operations,
       messages and  per-object  status  with  complete  object  identification  collected  during  LVM  command
       execution. 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 column 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/suffix
              - global/units
              - report/aligned
              - report/binary_values_as_numeric
              - report/columns_as_rows
              - report/compact_output
              - report/compact_output_cols
              - report/headings
              - report/list_item_separator
              - report/mark_hidden_devices
              - report/output_format
              - report/prefixes
              - report/quoted
              - report/separator
              - report/time_format
              - 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 of fields to use

              -o|--options FieldSet
                     Field set to use. See main report specifics and log report specifics for information  about
                     field sets configured with global configuration settings that this option overrides.

              -o|--options +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.

              -o|--options -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.

              -o|--options #FieldSet
                     Compaction of unused fields. Overrides report/compact_output_cols configuration setting.

       Sorting

              -O|--sort +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.

              -O|--sort -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

              -S|--select Selection
                     Define  selection  criteria  for  report  output.  For  log  report,  this  also  overrides
                     log/command_log_selection configuration setting, see also log report specifics.

       Changing output format and composition

              --reportformat
                     Overrides report/output_format configuration setting.

              --aligned
                     Overrides report/aligned configuration setting.

              --binary
                     Overrides report/binary_values_as_numeric configuration setting.  TP  --headings  Overrides
                     report/headings configuration settings.

              --nameprefixes
                     Overrides report/prefixes configuration setting.

              --noheadings
                     Overrides report/headings configuration setting.

              --nosuffix
                     Overrides global/suffix configuration setting.

              --rows Overrides report/columns_as_rows configuration setting.

              --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 subsequent -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/buffered 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, referenced by their name -  ReportName  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 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 particularly 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
       addition  to  usual  configuration  settings  for  report  fields  and  sorting,  the log report has also
       configuration option for selection - report/command_log_selection. This configuration setting is provided
       for  convenience  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=success)".  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. To see unfiltered
       command log, use "all" value for the selection. 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 output  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 initialization 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
       descriptors 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
                     Return code associated with current item.

       You can also run lvm --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 selection 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 -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 -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 suffix (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  automatically  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", "yesterday")
          -  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 STATEMENT | (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 different 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 configuration 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
       fullreport(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.

       # 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 configuring  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/output_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 example) 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
       configuration 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 --withcomments report/time_format 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).

       # 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

       In  certain  cases, you may find it more useful to report full column names instead of abbreviated column
       names in report headings. To do this, use report/headings=2 configuration setting (or --headings full  or
       --headings  2  command  line  option).  The  full  column  names are the exact names that you also use in
       FieldSet for -o|--options.  These names are unambiguous, without spaces (one word  only)  and  they  also
       make it easier to match the output with requested FieldSet:

       # lvs -o+seg_start,seg_start_pe
         LV    VG LSize Cpy%Sync Start Start
         lvol0 vg 4.00m             0      0
         lvol1 vg 4.00m 100.00      0      0

       # lvs --headings full -o+seg_start,seg_start_pe
         lv_name vg_name lv_size copy_percent seg_start seg_start_pe
         lvol0   vg        4.00m                     0             0
         lvol1   vg        4.00m 100.00              0             0

   Changing output format
       LVM  can  output  reports  in  different  formats  -  use  report/output_format configuration setting (or
       --reportformat command line option) to switch the report output format.

       Currently, LVM supports these output formats:
              - "basic" (all the examples we used above used this format),
              - "json",
              - "json_std".

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

       The json_std output format is more compliant with JSON standard and compared to the original json format:
              - it does not use double quotes around numeric values,
              - numeric values are always expressed as numbers, not reserved strings
                representing them (this also means that report/binary_values_as_numeric=1
                setting is forced)
              - it uses 'null' for undefined numeric values,
              - it prints string list as proper JSON array of strings instead of a single string.

       Note that some configuration settings and command  line  options  have  no  effect  with  certain  report
       formats.  For  example,  with  json or json_std 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
       or json_std report output format.

   Selection
       If you need to select only specific rows from report, you can use LVM's report selection feature. If  you
       call  lvm  -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 demonstrate 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 delimiter 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 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.

       # 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 subreport here.

       Below is an extended example with lvm fullreport 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 interested only in PV  names  having  "sda"  in  their
       name.  For  the  "log"  subreport  we're interested 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.

       # 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), lvcreate(8),
       lvs(8), pvs(8), vgs(8),

       date(1), strftime(3)