Provided by: lvm2_2.02.98-6ubuntu2_amd64 bug


       lvm - LVM2 tools


       lvm [command | file]


       lvm  provides  the  command-line  tools  for  LVM2.  A separate manual page describes each
       command in detail.

       If lvm is invoked with no arguments  it  presents  a  readline  prompt  (assuming  it  was
       compiled with readline support).  LVM commands may be entered interactively at this prompt
       with readline facilities including history and command name and option completion.   Refer
       to readline(3) for details.

       If  lvm  is invoked with argv[0] set to the name of a specific LVM command (for example by
       using a hard or soft link) it acts as that command.

       On invocation, lvm requires that only the standard  file  descriptors  stdin,  stdout  and
       stderr  are  available.   If  others  are  found,  they get closed and messages are issued
       warning about the leak.

       Where commands take VG or LV names as arguments, the full path name is  optional.   An  LV
       called  "lvol0" in a VG called "vg0" can be specified as "vg0/lvol0".  Where a list of VGs
       is required but is left empty, a list of all VGs will be substituted.  Where a list of LVs
       is  required  but a VG is given, a list of all the LVs in that VG will be substituted.  So
       lvdisplay vg0 will display all the LVs in "vg0".  Tags can also be  used  -  see  --addtag

       One  advantage  of  using the built-in shell is that configuration information gets cached
       internally between commands.

       A file containing a simple script with one command per line  can  also  be  given  on  the
       command  line.   The script can also be executed directly if the first line is #! followed
       by the absolute path of lvm.


       The following commands are built into lvm without links  normally  being  created  in  the
       filesystem for them.

       dumpconfig — Display the configuration information after
              loading lvm.conf(5) and any other configuration files.

       formats — Display recognised metadata formats.

       help — Display the help text.

       pvdata — Not implemented in LVM2.

       segtypes — Display recognised Logical Volume segment types.

       version — Display version information.


       The following commands implement the core LVM functionality.

       pvchange — Change attributes of a Physical Volume.

       pvck — Check Physical Volume metadata.

       pvcreate — Initialize a disk or partition for use by LVM.

       pvdisplay — Display attributes of a Physical Volume.

       pvmove — Move Physical Extents.

       pvremove — Remove a Physical Volume.

       pvresize — Resize a disk or partition in use by LVM2.

       pvs — Report information about Physical Volumes.

       pvscan — Scan all disks for Physical Volumes.

       vgcfgbackup — Backup Volume Group descriptor area.

       vgcfgrestore — Restore Volume Group descriptor area.

       vgchange — Change attributes of a Volume Group.

       vgck — Check Volume Group metadata.

       vgconvert — Convert Volume Group metadata format.

       vgcreate — Create a Volume Group.

       vgdisplay — Display attributes of Volume Groups.

       vgexport — Make volume Groups unknown to the system.

       vgextend — Add Physical Volumes to a Volume Group.

       vgimport — Make exported Volume Groups known to the system.

       vgimportclone — Import and rename duplicated Volume Group (e.g. a hardware snapshot).

       vgmerge — Merge two Volume Groups.

       vgmknodes — Recreate Volume Group directory and Logical Volume special files

       vgreduce — Reduce a Volume Group by removing one or more
              Physical Volumes.

       vgremove — Remove a Volume Group.

       vgrename — Rename a Volume Group.

       vgs — Report information about Volume Groups.

       vgscan — Scan all disks for Volume Groups and rebuild caches.

       vgsplit — Split a Volume Group into two, moving any logical
              volumes from one Volume Group to another by moving entire Physical Volumes.

       lvchange — Change attributes of a Logical Volume.

       lvconvert — Convert a Logical Volume from linear to mirror or snapshot.

       lvcreate — Create a Logical Volume in an existing Volume Group.

       lvdisplay — Display attributes of a Logical Volume.

       lvextend — Extend the size of a Logical Volume.

       lvmchange — Change attributes of the Logical Volume Manager.

       lvmdiskscan — Scan for all devices visible to LVM2.

       lvmdump — Create lvm2 information dumps for diagnostic purposes.

       lvreduce — Reduce the size of a Logical Volume.

       lvremove — Remove a Logical Volume.

       lvrename — Rename a Logical Volume.

       lvresize — Resize a Logical Volume.

       lvs — Report information about Logical Volumes.

       lvscan — Scan (all disks) for Logical Volumes.

       The  following  commands  are not implemented in LVM2 but might be in the future: lvmsadc,
       lvmsar, pvdata.


       The following options are available for  many  of  the  commands.   They  are  implemented
       generically and documented here rather than repeated on individual manual pages.

       -h, --help
              Display the help text.

              Display version information.

       -v, --verbose
              Set verbose level. Repeat from 1 to 3 times to increase the detail of messages sent
              to stdout and stderr.  Overrides config file setting.

       -d, --debug
              Set debug level. Repeat from 1 to 6 times to increase the detail of  messages  sent
              to the log file and/or syslog (if configured).  Overrides config file setting.

       -q, --quiet
              Suppress output and log messages.  Overrides -d and -v.

       -t, --test
              Run  in  test  mode.  Commands  will  not  update metadata.  This is implemented by
              disabling all metadata writing but nevertheless returning success  to  the  calling
              function.   This  may lead to unusual error messages in multi-stage operations if a
              tool relies on reading back metadata it believes has changed but hasn't.

       --driverloaded {y|n}
              Whether or not the device-mapper kernel driver is loaded.  If you set this to n, no
              attempt will be made to contact the driver.

       -A, --autobackup {y|n}
              Whether  or  not to metadata should be backed up automatically after a change.  You
              are strongly advised not to disable this!  See vgcfgbackup(8).

       -P, --partial
              When set, the tools will do their best to provide access to Volume Groups that  are
              only  partially  available  (one  or  more Physical Volumes belonging to the Volume
              Group are missing from the system).  Where part of a  logical  volume  is  missing,
              /dev/ioerror  will  be  substituted, and you could use dmsetup(8) to set this up to
              return I/O errors when accessed, or create it as a large  block  device  of  nulls.
              Metadata  may  not  be  changed  with this option. To insert a replacement Physical
              Volume of the same or large size use pvcreate -u to  set  the  uuid  to  match  the
              original followed by vgcfgrestore(8).

       -M, --metadatatype Type
              Specifies which type of on-disk metadata to use, such as lvm1 or lvm2, which can be
              abbreviated to 1 or 2 respectively.  The default (lvm2) can be changed  by  setting
              format in the global section of the config file.

              This  lets  you proceed with read-only metadata operations such as lvchange -ay and
              vgchange -ay even if the locking module fails.  One use for this  is  in  a  system
              init script if the lock directory is mounted read-only when the script runs.

       --addtag Tag
              Add the tag Tag to a PV, VG or LV.  Supply this argument multiple times to add more
              than one tag at once.  A tag is a word that can be used to group  LVM2  objects  of
              the  same  type together.  Tags can be given on the command line in place of PV, VG
              or LV arguments.  Tags should be prefixed with @ to avoid ambiguity.  Each  tag  is
              expanded by replacing it with all objects possessing that tag which are of the type
              expected by its position on the command line.  PVs can only possess tags while they
              are part of a Volume Group: PV tags are discarded if the PV is removed from the VG.
              As an example, you could tag some LVs as database and others as userdata  and  then
              activate  the  database  ones  with  lvchange  -ay  @database.  Objects can possess
              multiple tags simultaneously.  Only the new LVM2 metadata format supports  tagging:
              objects  using the LVM1 metadata format cannot be tagged because the on-disk format
              does not support it.  Characters allowed in tags are: A-Z a-z 0-9 _ + . - and as of
              version 2.02.78 the following characters are also accepted: / = ! : # &

       --deltag Tag
              Delete  the  tag  Tag  from  a PV, VG or LV, if it's present.  Supply this argument
              multiple times to remove more than one tag at once.

       --alloc AllocationPolicy
              The allocation policy to use: contiguous, cling, normal, anywhere or inherit.  When
              a  command needs to allocate Physical Extents from the Volume Group, the allocation
              policy controls how they are chosen.  Each Volume Group and Logical Volume  has  an
              allocation  policy defined.  The default for a Volume Group is normal which applies
              common-sense rules such as not  placing  parallel  stripes  on  the  same  Physical
              Volume.   The default for a Logical Volume is inherit which applies the same policy
              as for the Volume Group.  These policies  can  be  changed  using  lvchange(8)  and
              vgchange(8)  or  overridden  on  the  command  line  of  any  command that performs
              allocation.  The contiguous policy requires that new  Physical  Extents  be  placed
              adjacent  to  existing  Physical  Extents.   The  cling  policy places new Physical
              Extents on the same Physical Volume as existing Physical Extents in the same stripe
              of the Logical Volume.  If there are sufficient free Physical Extents to satisfy an
              allocation request but normal doesn't use  them,  anywhere  will  -  even  if  that
              reduces performance by placing two stripes on the same Physical Volume.


       HOME   Directory containing .lvm_history if the internal readline shell is invoked.

              Directory   containing  lvm.conf(5)  and  other  LVM  system  files.   Defaults  to

              The Volume Group name that is assumed for any reference to a  Logical  Volume  that
              doesn't specify a path.  Not set by default.


       The following characters are valid for VG and LV names: a-z A-Z 0-9 + _ . -

       VG  and  LV  names cannot begin with a hyphen.  There are also various reserved names that
       are used internally by lvm that can not be used as LV or VG names.  A VG cannot be  called
       anything  that  exists in /dev/ at the time of creation, nor can it be called '.' or '..'.
       A LV cannot be called '.' '..' 'snapshot' or 'pvmove'. The LV name may  also  not  contain
       the strings '_mlog', '_mimage', '_rimage', '_tdata', '_tmeta'.


       When  an operation needs to allocate Physical Extents for one or more Logical Volumes, the
       tools proceed as follows:

       First of all, they generate the complete set of unallocated Physical Extents in the Volume
       Group.   If  any  ranges  of Physical Extents are supplied at the end of the command line,
       only unallocated Physical Extents within those ranges on the  specified  Physical  Volumes
       are considered.

       Then  they  try  each  allocation  policy  in  turn,  starting  with  the strictest policy
       (contiguous) and ending with the allocation policy specified using --alloc or set  as  the
       default  for  the  particular  Logical Volume or Volume Group concerned.  For each policy,
       working from the lowest-numbered Logical Extent of the empty  Logical  Volume  space  that
       needs  to be filled, they allocate as much space as possible according to the restrictions
       imposed by the policy.  If more space is needed, they move on to the next policy.

       The restrictions are as follows:

       Contiguous requires that the physical location of any Logical Extent that is not the first
       Logical  Extent  of  a  Logical Volume is adjacent to the physical location of the Logical
       Extent immediately preceding it.

       Cling requires that the Physical Volume used for any Logical Extent  to  be  added  to  an
       existing  Logical  Volume is already in use by at least one Logical Extent earlier in that
       Logical Volume.  If the configuration parameter allocation/cling_tag_list is defined, then
       two  Physical Volumes are considered to match if any of the listed tags is present on both
       Physical Volumes.  This allows groups of Physical Volumes with similar properties (such as
       their physical location) to be tagged and treated as equivalent for allocation purposes.

       When  a  Logical  Volume  is  striped  or  mirrored,  the  above  restrictions are applied
       independently to each stripe or mirror image (leg) that needs space.

       Normal will not choose a Physical Extent that shares the same Physical Volume as a Logical
       Extent  already  allocated to a parallel Logical Volume (i.e. a different stripe or mirror
       image/leg) at the same offset within that parallel Logical Volume.

       When allocating a mirror log at the same time as Logical Volumes to hold the mirror  data,
       Normal  will  first try to select different Physical Volumes for the log and the data.  If
       that's not  possible  and  the  allocation/mirror_logs_require_separate_pvs  configuration
       parameter is set to 0, it will then allow the log to share Physical Volume(s) with part of
       the data.

       When allocating thin pool metadata, similar considerations to those of a mirror log in the
       last       paragraph       apply       based       on      the      value      of      the
       allocation/thin_pool_metadata_require_separate_pvs configuration parameter.

       If you rely upon any layout behaviour beyond that documented here, be aware that it  might
       change in future versions of the code.

       For  example,  if  you  supply on the command line two empty Physical Volumes that have an
       identical number of free Physical Extents  available  for  allocation,  the  current  code
       considers  using each of them in the order they are listed, but there is no guarantee that
       future releases will maintain that property.  If it is  important  to  obtain  a  specific
       layout  for a particular Logical Volume, then you should build it up through a sequence of
       lvcreate(8) and lvconvert(8) steps such that the restrictions described above  applied  to
       each step leave the tools no discretion over the layout.

       To  view  the  way  the  allocation process currently works in any specific case, read the
       debug logging output, for example by adding -vvvv to a command.


       All tools return a status code of zero on success or non-zero on failure.




       clvmd(8),   lvchange(8),    lvcreate(8),    lvdisplay(8),    lvextend(8),    lvmchange(8),
       lvmdiskscan(8),  lvreduce(8),  lvremove(8),  lvrename(8),  lvresize(8), lvs(8), lvscan(8),
       pvchange(8),  pvck(8),  pvcreate(8),   pvdisplay(8),   pvmove(8),   pvremove(8),   pvs(8),
       pvscan(8),  vgcfgbackup(8), vgchange(8), vgck(8), vgconvert(8), vgcreate(8), vgdisplay(8),
       vgextend(8),  vgimport(8),  vgimportclone(8),   vgmerge(8),   vgmknodes(8),   vgreduce(8),
       vgremove(8), vgrename(8), vgs(8), vgscan(8), vgsplit(8), readline(3), lvm.conf(5)