lvchange.1m (2010 09)

l
lvchange(1M) lvchange(1M)
NAME
lvchange - change characteristics on a LVM logical volume or snapshot volume
SYNOPSIS
For Logical Volumes
/usr/sbin/lvchange
[-a availability ][-A autobackup ][
-c mirror_consistency][
-C contiguous ]
[
-d schedule ][-D distributed ][
-M mirror_write_cache][
-p permission ][-r relocate ][-s
strict ][-t IO_timeout ] lv_path
For Snapshot Volumes -- on VG Version 2.2 and Higher
/usr/sbin/lvchange
[-a availability ][-A
autobackup ][-c mirror_consistency]
[
-e auto_prealloc_enabled][
-M mirror_write_cache][
-p permission ][-P threshold_value]
[
-t IO_timeout ] lv_path
Remarks
Mirrored disk operations require the installation of the optional HP MirrorDisk/UX software, which is not
included in the standard HP-UX operating system.
DESCRIPTION
The lvchange command changes certain characteristics of a logical volume or snapshot volume. Other
characteristics can be changed with the
lvextend and lvreduce commands (see lvextend (1M) and
lvreduce (1M)).
The command-line options specify the type and scope of change. Each current characteristic for a logical
volume remains in effect until explicitly changed by the corresponding option. All options take effect
immediately, except
-s, which takes effect only when new extents are allocated by the
lvextend com-
mand.
If a logical volume is striped, its scheduling policy is always parallel and its allocation policy is either
strict and noncontiguous or PVG-strict and noncontiguous; these attributes cannot be changed with
lvchange except the strict allocation policy of the striped Logical Volume.
The
lvchange command can also be used to change the timeout value for a logical volume. This can be
useful to control how long an IO request will be retried (for a transient error, like a device timeout),
before giving up and declaring a pending IO to be failed. The default behavior is for the system to con-
tinue to retry an IO for a transient error until the IO can complete. Thus, the IO will not be returned to
the caller until the IO can complete. By setting a non-zero IO timeout value, this will set the maximum
length of time that the system will retry an IO. If the IO cannot complete before the length of time
specified by the IO timeout, then the IO will be returned to the caller with an error.
The actual duration of the IO request may exceed the logical volume’s maximum IO timeout value when
the underlying physical volume(s) have timeouts which either exceed the logical volume’s timeout value or
are not an integer multiple of the logical volume’s timeout value (see pvchange (1M) for details on how to
change the IO timeout value on a physical volume).
lvchange on Snapshot Volumes
If the logical volume is a snapshot volume, then only its availability, access permission, IO timeout, and
MCR/MWC attributes can be changed with
lvchange. The automatic increase of pre-allocated extents
for space efficient snapshots can be enabled and the threshold value can be set or changed using
lvchange. If the threshold value is not specified, then a default threshold value is set. See lvm (7) for
details about snapshot volumes and default threshold values.
Options and Arguments
The
-c, -d, -M, and -s options are meaningful only if the optional HP MirrorDisk/UX software has been
installed on the system.
lvchange recognizes the following options and arguments:
lv_path The block device path name of a logical volume or a snapshot volume.
-a availability Set logical volume availability. availability can have one of the following
values:
y Make a logical volume available. An open of the logical volume will
succeed.
n Make a logical volume temporarily unavailable. An open of the log-
ical volume will fail. However, all current processes that have the
HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1