Ubuntu Manpage: lvchange — change attributes of a logical volume

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