Ubuntu Manpage: lvchange — change attributes of a logical volume

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Provided by: lvm2_2.02.133-1ubuntu10_amd64

NAME

       lvchange — change attributes of a logical volume

SYNOPSIS

       lvchange [-a|--activate [a][e|s|l]{y|n}] [--activationmode {complete|degraded|partial}] [--addtag Tag]
       [-K|--ignoreactivationskip] [-k|--setactivationskip {y|n}] [--alloc AllocationPolicy] [-A|--autobackup
       {y|n}] [--cachepolicy policy] [--cachesettings key=value] [--commandprofile ProfileName] [-C|--contiguous
       {y|n}] [-d|--debug] [--degraded] [--deltag Tag] [--detachprofile] [--discards
       {ignore|nopassdown|passdown}] [--errorwhenfull {y|n}] [-h|-?|--help] [--ignorelockingfailure]
       [--ignoremonitoring] [--ignoreskippedcluster] [--metadataprofile ProfileName] [--monitor {y|n}]
       [--noudevsync] [-P|--partial] [-p|--permission {r|rw}] [-M|--persistent {y|n} [--major major] [--minor
       minor]] [--poll {y|n}] [--[raid]maxrecoveryrate Rate] [--[raid]minrecoveryrate Rate] [--[raid]syncaction
       {check|repair}] [--[raid]writebehind IOCount] [--[raid]writemostly PhysicalVolume[:{y|n|t}]]
       [-r|--readahead {ReadAheadSectors|auto|none}] [--refresh] [--resync] [-S|--select Selection] [--sysinit]
       [-t|--test] [-v|--verbose] [-Z|--zero {y|n}] [LogicalVolumePath...]

DESCRIPTION

       lvchange  allows  you  to  change  the  attributes of a logical volume including making them known to the
       kernel ready for use.

OPTIONS

See lvm(8) for common options.

-a|--activate [a][e|s|l]{y|n}
Controls the availability of the logical volumes for use. Communicates with the kernel device-
mapper driver via libdevmapper to activate (-ay) or deactivate (-an) the logical volumes.
Activation of a logical volume creates a symbolic link /dev/VolumeGroupName/LogicalVolumeName
pointing to the device node. This link is removed on deactivation. All software and scripts
should access the device through this symbolic link and present this as the name of the device.
The location and name of the underlying device node may depend on the distribution and
configuration (e.g. udev) and might change from release to release.
If autoactivation option is used (-aay), the logical volume is activated only if it matches an
item in the activation/auto_activation_volume_list set in lvm.conf(5). If this list is not set,
then all volumes are considered for activation. The -aay option should be also used during system
boot so it's possible to select which volumes to activate using the
activation/auto_activation_volume_list setting.
In a clustered VG, clvmd is used for activation, and the following options are possible:

With -aey, clvmd activates the LV in exclusive mode (with an exclusive lock), allowing a single
node to activate the LV.

With -asy, clvmd activates the LV in shared mode (with a shared lock), allowing multiple nodes to
activate the LV concurrently. If the LV type prohibits shared access, such as an LV with a
snapshot, the 's' option is ignored and an exclusive lock is used.

With -ay (no mode specified), clvmd activates the LV in shared mode if the LV type allows
concurrent access, such as a linear LV. Otherwise, clvmd activates the LV in exclusive mode.

With -aey, -asy, and -ay, clvmd attempts to activate the LV on all nodes. If exclusive mode is
used, then only one of the nodes will be successful.

With -an, clvmd attempts to deactivate the LV on all nodes.

With -aly, clvmd activates the LV only on the local node, and -aln deactivates only on the local
node. If the LV type allows concurrent access, then shared mode is used, otherwise exclusive.

LVs with snapshots are always activated exclusively because they can only be used on one node at
once.

For local VGs -ay, -aey, and -asy are all equivalent.

--activationmode {complete|degraded|partial}
The activation mode determines whether logical volumes are allowed to activate when there are
physical volumes missing (e.g. due to a device failure). complete is the most restrictive;
allowing only those logical volumes to be activated that are not affected by the missing PVs.
degraded allows RAID logical volumes to be activated even if they have PVs missing. (Note that
the "mirror" segment type is not considered a RAID logical volume. The "raid1" segment type
should be used instead.) Finally, partial allows any logical volume to be activated even if
portions are missing due to a missing or failed PV. This last option should only be used when
performing recovery or repair operations. degraded is the default mode. To change it, modify
activation_mode in lvm.conf(5).

-K|--ignoreactivationskip
Ignore the flag to skip Logical Volumes during activation.

-k|--setactivationskip {y|n}
Controls whether Logical Volumes are persistently flagged to be skipped during activation. By
default, thin snapshot volumes are flagged for activation skip. To activate such volumes, an
extra --ignoreactivationskip option must be used. The flag is not applied during deactivation. To
see whether the flag is attached, use lvs(8) command where the state of the flag is reported
within lv_attr bits.

--cachepolicy policy, --cachesettings key=value
Only applicable to cached LVs; see also lvmcache(7). Sets the cache policy and its associated
tunable settings. In most use-cases, default values should be adequate.

-C|--contiguous {y|n}
Tries to set or reset the contiguous allocation policy for logical volumes. It's only possible to
change a non-contiguous logical volume's allocation policy to contiguous, if all of the allocated
physical extents are already contiguous.

--detachprofile
Detach any metadata configuration profiles attached to given Logical Volumes. See lvm.conf(5) for
more information about metadata profiles.

--discards {ignore|nopassdown|passdown}
Set this to ignore to ignore any discards received by a thin pool Logical Volume. Set to
nopassdown to process such discards within the thin pool itself and allow the no-longer-needed
extents to be overwritten by new data. Set to passdown (the default) to process them both within
the thin pool itself and to pass them down the underlying device.

--errorwhenfull {y|n}
Sets thin pool behavior when data space is exhaused. See lvcreate(8) for information.

--ignoremonitoring
Make no attempt to interact with dmeventd unless --monitor is specified. Do not use this if
dmeventd is already monitoring a device.

--major major
Sets the major number. This option is supported only on older systems (kernel version 2.4) and is
ignored on modern Linux systems where major numbers are dynamically assigned.

--minor minor
Set the minor number.

--metadataprofile ProfileName
Uses and attaches ProfileName configuration profile to the logical volume metadata. Whenever the
logical volume is processed next time, the profile is automatically applied. If the volume group
has another profile attached, the logical volume profile is preferred. See lvm.conf(5) for more
information about metadata profiles.

--monitor {y|n}
Start or stop monitoring a mirrored or snapshot logical volume with dmeventd, if it is installed.
If a device used by a monitored mirror reports an I/O error, the failure is handled according to
mirror_image_fault_policy and mirror_log_fault_policy set in lvm.conf(5).

--noudevsync
Disable udev synchronisation. The process will not wait for notification from udev. It will
continue irrespective of any possible udev processing in the background. You should only use this
if udev is not running or has rules that ignore the devices LVM2 creates.

-p|--permission {r|rw}
Change access permission to read-only or read/write.

-M|--persistent {y|n}
Set to y to make the minor number specified persistent. Change of persistent numbers is not
supported for pool volumes.

--poll {y|n}
Without polling a logical volume's backgrounded transformation process will never complete. If
there is an incomplete pvmove or lvconvert (for example, on rebooting after a crash), use --poll y
to restart the process from its last checkpoint. However, it may not be appropriate to
immediately poll a logical volume when it is activated, use --poll n to defer and then --poll y to
restart the process.

--[raid]maxrecoveryrate Rate[b|B|s|S|k|K|m|M|g|G]
Sets the maximum recovery rate for a RAID logical volume. Rate is specified as an amount per
second for each device in the array. If no suffix is given, then KiB/sec/device is assumed.
Setting the recovery rate to 0 means it will be unbounded.

--[raid]minrecoveryrate Rate[b|B|s|S|k|K|m|M|g|G]
Sets the minimum recovery rate for a RAID logical volume. Rate is specified as an amount per
second for each device in the array. If no suffix is given, then KiB/sec/device is assumed.
Setting the recovery rate to 0 means it will be unbounded.

--[raid]syncaction {check|repair}
This argument is used to initiate various RAID synchronization operations. The check and repair
options provide a way to check the integrity of a RAID logical volume (often referred to as
"scrubbing"). These options cause the RAID logical volume to read all of the data and parity
blocks in the array and check for any discrepancies (e.g. mismatches between mirrors or incorrect
parity values). If check is used, the discrepancies will be counted but not repaired. If repair
is used, the discrepancies will be corrected as they are encountered. The lvs(8) command can be
used to show the number of discrepancies found or repaired.

--[raid]writebehind IOCount
Specify the maximum number of outstanding writes that are allowed to devices in a RAID1 logical
volume that are marked as write-mostly. Once this value is exceeded, writes become synchronous
(i.e. all writes to the constituent devices must complete before the array signals the write has
completed). Setting the value to zero clears the preference and allows the system to choose the
value arbitrarily.

--[raid]writemostly PhysicalVolume[:{y|n|t}]
Mark a device in a RAID1 logical volume as write-mostly. All reads to these drives will be
avoided unless absolutely necessary. This keeps the number of I/Os to the drive to a minimum.
The default behavior is to set the write-mostly attribute for the specified physical volume in the
logical volume. It is possible to also remove the write-mostly flag by appending a ":n" to the
physical volume or to toggle the value by specifying ":t". The --writemostly argument can be
specified more than one time in a single command; making it possible to toggle the write-mostly
attributes for all the physical volumes in a logical volume at once.

-r|--readahead {ReadAheadSectors|auto|none}
Set read ahead sector count of this logical volume. For volume groups with metadata in lvm1
format, this must be a value between 2 and 120 sectors. The default value is "auto" which allows
the kernel to choose a suitable value automatically. "none" is equivalent to specifying zero.

--refresh
If the logical volume is active, reload its metadata. This is not necessary in normal operation,
but may be useful if something has gone wrong or if you're doing clustering manually without a
clustered lock manager.

--resync
Forces the complete resynchronization of a mirror. In normal circumstances you should not need
this option because synchronization happens automatically. Data is read from the primary mirror
device and copied to the others, so this can take a considerable amount of time - and during this
time you are without a complete redundant copy of your data.

--sysinit
Indicates that lvchange(8) is being invoked from early system initialisation scripts (e.g.
rc.sysinit or an initrd), before writeable filesystems are available. As such, some functionality
needs to be disabled and this option acts as a shortcut which selects an appropriate set of
options. Currently this is equivalent to using --ignorelockingfailure, --ignoremonitoring, --poll
n and setting LVM_SUPPRESS_LOCKING_FAILURE_MESSAGES environment variable.

If --sysinit is used in conjunction with lvmetad(8) enabled and running, autoactivation is
preferred over manual activation via direct lvchange call. Logical volumes are autoactivated
according to
auto_activation_volume_list set in lvm.conf(5).

-Z|--zero {y|n}
Set zeroing mode for thin pool. Note: already provisioned blocks from pool in non-zero mode are
not cleared in unwritten parts when setting zero to y.

ENVIRONMENT VARIABLES

       LVM_SUPPRESS_LOCKING_FAILURE_MESSAGES
              Suppress locking failure messages.

Examples

       Changes the permission on volume lvol1 in volume group vg00 to be read-only:

       lvchange -pr vg00/lvol1