Learn the UNIX/Linux command line
Home Man Pages
LVM(8) LVM(8)
NAME
lvm - LVM2 tools
SYNOPSIS
lvm [command | file]
DESCRIPTION
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 includ-
ing history and command name and option completion. Refer to read-
line(3) for details.
If lvm is invoked with argv[0] set to the name of a specific LVM com-
mand (for example by using a hard or soft link) it acts as that com-
mand.
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 substi-
tuted. 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 infor-
mation 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.
BUILT-IN COMMANDS
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 (8) 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 are not implemented in LVM2 but might be in
future: lvmsadc, lvmsar, pvdata, pvresize.
OPTIONS
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 dis-
abling all metadata writing but nevertheless returning success
to the calling function. This may lead to unusual error mes-
sages 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 argu-
ments. Tags should be prefixed with @ to avoid ambiguity.
Each tag is expanded by replacing it with all objects possess-
ing 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 sup-
ports tagging: objects using the LVM1 metadata format cannot be
tagged because the on-disk format does not support it. Snap-
shots 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, 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 allo-
cation 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 are adjacent to existing extents. If there are suf-
ficient free extents to satisfy an allocation request but nor-
mal doesn't use them, anywhere will - even if that reduces per-
formance by placing two stripes on the same physical volume.
N.B. The policies described above are not implemented fully
yet. In particular, contiguous does not place new extents
adjacent to existing extents and anywhere is not implemented at
all.
ENVIRONMENT VARIABLES
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.
DIAGNOSTICS
All tools return a status code of zero on success or non-zero on fail-
ure.
FILES
/etc/lvm/lvm.conf
$HOME/.lvm_history
SEE ALSO
clvmd(8), lvchange(8), lvcreate(8), lvdisplay(8), lvextend(8), lvm-
change(8), lvmdiskscan(8), lvreduce(8), lvremove(8), lvrename(8),
lvresize(8), lvs(8), lvscan(8), pvchange(8), pvcreate(8), pvdis-
play(8), pvmove(8), pvremove(8), pvs(8), pvscan(8), vgcfgbackup(8),
vgchange(8), vgck(8), vgconvert(8), vgcreate(8), vgdisplay(8), vgex-
tend(8), vgimport(8), vgmerge(8), vgmknodes(8), vgreduce(8), vgre-
move(8), vgrename(8), vgs(8), vgscan(8), vgsplit(8), readline(3),
lvm.conf(5)
Sistina Software UK LVM TOOLS LVM(8)
UNIX/Linux commands referenced on this page: