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.
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
  below.
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.
- 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.
- --version — 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.
- --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. 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.
- --ignorelockingfailure
- 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. 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.
      Snapshots cannot be tagged. Characters allowed in tags are: A-Z a-z 0-9 _
      + . -
- --deltag tag
- Delete the tag tag from a PV, VG or LV, if it's present.
- --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. 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
      over-ridden on the command line of any command that performs allocation.
      The contiguous policy requires that new extents be placed adjacent
      to existing extents. The cling policy places new extents on the
      same physical volume as existing extents in the same stripe of the Logical
      Volume. If there are sufficient free 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.
  
  - N.B. The policies described above are not implemented fully yet. In
      particular, contiguous free space cannot be broken up to satisfy
      allocation attempts.
  - LVM_SYSTEM_DIR
- Directory containing lvm.conf and other LVM system files. Defaults to
      "/etc/lvm".
- HOME
- Directory containing .lvm_history if the internal readline shell is
      invoked.
- LVM_VG_NAME
- 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'
    or '_mimage'
All tools return a status code of zero on success or non-zero on failure.
/etc/lvm/lvm.conf
$HOME/.lvm_history
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),
  vgmerge(8), vgmknodes(8), vgreduce(8),
  vgremove(8), vgrename(8), vgs(8), vgscan(8),
  vgsplit(8), readline(3), lvm.conf(5)