lvchange(1M) — Series 800 Only

NAME

lvchange − change logical volume characteristics

SYNOPSIS

/etc/lvchange [-a availability] [-d schedule] [-p permission] [-r relocate] [-s strict] [-C contiguous] [-M mirror_write_cache] [-c mirror_consistency] lv_path

DESCRIPTION

lvchange changes the characteristics of a logical volume. Optional command-line options and parameters specify the type and extent of change. Each current characteristic for a logical volume remains in effect until explicitly changed by the corresponding command option. All options take effect immediately except -s which takes effect only when new extents are allocated by the lvextend command (see lvextend(1M)). lv_path must be a logical volume name.

Options

lvchange recognizes the following options and parameters:

-a availability Set Logical Volume availability. availability can have one of the following values:

y Make a logical volume available; that is, an open of the logical volume will succeed.

n Make a logical volume temporarily unavailable; that is, an open of the logical volume will fail; however, all current processes that have the logical volume open remain open.

-d schedule Set scheduling policy when a logical extent with more than one mirror is written. schedule can have one of the following values:

p Establish a parallel scheduling policy.

s Establish a sequential scheduling policy. Use this value with care because it leads to performance loss in most cases.

-p permission Set access permission to read-write or read-only. permission can have one of the following values:

w Set access permission to read-write.

r Set access permission to read-only.

-r relocate Set the bad block relocation policy. relocate can have one of the following values:

y Allow bad block relocation.

n Prevent bad block relocation.

-s strict Specify the strict allocation policy. Mirrors of a logical extent can be allocated to share or not share the same physical volume or physical volume group. This option only makes sense when the physical volumes of the volume group that owns the logical volume to be changed reside on different physical disks. strict can have one of the following values:

y Set a strict allocation policy: mirrors of a logical extent cannot share the same physical volume.

n Do not set a strict or PVG-strict allocation policy.

g Set a PVG-strict allocation policy: mirrors of a logical extent cannot share the same physical volume group.

When the logical volume is mirrored, the following changes are not allowed:

• from non-strict to strict,

• from non-strict to PVG-strict,

• from strict to PVG-strict.

-C contiguous Specify the contiguous allocation policy. Physical extents are allocated in ascending order without any gap between adjacent extents and all extents are contained in a single physical volume. contiguous can have one of the following values:

y Set a contiguous allocaton policy.

n Do not set a contiguous allocation policy.

A non-empty logical volume that has a non-contiguous allocation policy cannot be changed to a contiguous allocaton policy unless it happens to meet all the requirements of the contiguous allocation policy. The strict (-s) and contiguous (-C) options can be used together to change two allocation policies at the same time.

See lvcreate(1m) for more information about contiguous allocation policy.

-M mirror_write_cache
Set the Mirror Write Cache to on or off. This option is allowed only when the logical volume is not opened. mirror_write_cache can have one of the following values:

y Set Mirror Write Cache to on. Every write to a mirror copy is recorded in the Mirror Write Cache and written into the Mirror Consistency Record on the disk if a cache-miss occurred. This allows LVM to determine whether all mirror copies are identical, even across system crashes. When the volume group is activated, the Mirror Consistency Record is used to perform mirror consistency recovery.

n Set Mirror Write Cache to off. Mirror write does not incur an additional write to the Mirror Consistency Record on the disk.

-c mirror_consistency
Set mirror consistency recovery to on or off. This option only makes sense when -M n is specified, or when the Mirror Write Cache has already been turned off on the logical volume. mirror_consistency can have one of the following values:

y Set mirror consistency recovery to on. LVM achieves mirror consistency during volume group activation by going through all logical extents and copying data from a non-stale copy to the other mirror copy.

n Set mirror consistency recovery to off. LVM does not perform mirror consistency recovery on this logical volume when the volume group is activated.

EXTERNAL INFLUENCES

Environment Variables

LANG determines the language in which messages are displayed.

If LANG is not specified or is set to the empty string, a default of "C" (see lang(5)) is used instead of LANG.

If any internationalization variable contains an invalid setting, lvchange behaves as if all internationalization variables are set to "C". See environ(5).

EXAMPLES

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

lvchange -p r /dev/vg01/lvol3

Change the allocation policy of a logical volume to non-strict:

lvchange -s n /dev/vg01/lvol7

Turn the mirror write cache off on a logical volume:

lvchange -M n /dev/vg01/lvol1

REMARKS

The -r option is not available on HP-IB devices.

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