lvchange.1m (2010 09)

lvchange(1M) lvchange(1M)

Shared Volume Group Considerations

For volume group version 1.0 and 2.0,

lvchange cannot be used if the volume group is activated in

shared mode. For volume groups version 2.1 (or higher),

lvchange can be performed when activated in

either shared, exclusive, or standalone mode.

Note that the

lvmpud daemon must be running on all the nodes sharing a volume group activated in

shared mode. See lvmpud(1M).

LVM shared mode is currently only available in Serviceguard clusters.

EXTERNAL INFLUENCES

Environment Variables

LANG determines the language in which messages are displayed.

LANG is not speciﬁed or is null, it defaults to "C" (see lang (5)).

If any internationalization variable contains an invalid setting, all internationalization variables default

to "C" (see environ (5)).

EXAMPLES

Change the permission of a logical volume to read-only:

lvchange -p r /dev/vg01/lvol3

Change the permission of a snapshot volume to read-write:

lvchange -p w /dev/vg01/lvol3_S4

Change the allocation policy of a logical volume to nonstrict:

lvchange -s n /dev/vg01/lvol7

Turn the mirror write cache off on a logical volume:

lvchange -M n /dev/vg01/lvol1

Change the IO timeout value of a logical volume to 1 minute (60 seconds):

lvchange -t 60 /dev/vg01/lvol1

Enable the automatic increase of pre-allocated extents and set the threshold value to 50% for a space

efﬁcient snapshot:

lvchange -e y -P 50 /dev/vg01/lvol3_S4

WARNINGS

For root, swap or dump logical volumes, the allocation policy is always contiguous. This attribute cannot

be changed with lvchange.

By setting mirror consistency recovery off, crash recovery time will be reduced. After a system crash the

mirrored logical volume will be available, but there may not be consistent data across each mirror copy.

The only types of data that can safely be put on a mirrored logical volume with mirror consistency

recovery turned off are:

• data not needed after a crash, such as swap or other raw scratch data, or

• data that an application itself will automatically reconstruct; for example, a raw logical volume for

which a database keeps a log of incomplete transactions.