lvmerge.1m (2010 09)

l
lvmerge(1M) lvmerge(1M)
(Requires Optional HP MirrorDisk/UX Software)
NAME
lvmerge - merge two LVM logical volumes into one logical volume
SYNOPSIS
/usr/sbin/lvmerge
[-A autobackup ][-s] copy_lv_path master_lv_path
Remarks
This command requires the installation of the optional HP MirrorDisk/UX software, which is not included
in the standard HP-UX operating system.
DESCRIPTION
The
lvmerge command merges two logical volumes of the same size. The copy_lv_path is added as a
mirrored copy of master_lv_path and only the master_lv_path logical volume is retained. The number of
mirrored copies of the master_lv_path is increased by the number of copies in the copy_lv_path .Either
copy_lv_path or master_lv_path must be an unmirrored logical volume.
Data previously contained in the copy_lv_path will be resynchronized using the data in the
master_lv_path. All new data on the copy_lv_path will be destroyed and the copy_lv_path logical volume
will be removed.
The
lvmerge command does not support merge of snapshot logical volumes. If the copy_lv_path or
master_lv_path is a snapshot logical volume, the
lvmerge command will fail. Also, if copy_lv_path or
master_lv_path is an original logical volume but has at least one snapshot associated with it, the
lvmverge command will fail. See lvm(7) for information about snapshot logical volumes.
By default,
lvmerge completes after all the extents are resynchronized. When run with the
-s option, if
there is no bitmap (see below),
lvmerge returns without resynchronizing the remaining logical volume.
Using the -s option may affect data high availability as extents may remain stale. Use
lvsync or
vgsync to synchronize the mirrors.
The normal usage for this command is to merge previously mirrored logical volumes that have been split
using the
lvsplit command. However, the two logical volumes are not required to have been the result
of a previous lvsplit operation.
NOTE: When a mirrored logical volume of a non-shared volume group is split into two logical volumes
using
lvsplit, a bitmap is stored that keeps track of all writes to either logical volume in the split pair.
If the volume group was shared at the time of the split, no bitmap was created. When the two logical
volumes are subsequently merged using lvmerge, the bitmap is used to decide which areas of
copy_lv_path need to be resynchronized with the master_lv_path. This bitmap remains in existence until
one of the following conditions occurs:
• The merge is completed.
• One of the logical volumes is extended, reduced, or split again.
• The volume group is deactivated, or cross-activated to shared mode (see vgchange (1M)).
• The system is rebooted.
If there is no bitmap available, all the physical extents from the copy_lv_path are marked stale. If there
is a bitmap available, the
-s option is ignored.
Options and Arguments
lvmerge recognizes the following options and arguments:
copy_lv_path The block device path name of a logical volume that will be removed.
master_lv_path The block device path name of a logical volume that will remain.
-A autobackup Set automatic backup for this invocation of this command. autobackup can have
one of the following values:
y Automatically back up configuration changes made to the logical volume.
This is the default.
After this command executes, the
vgcfgbackup command (see
vgcfgbackup (1M)) is executed for the volume group to which the logical
volume belongs.
n Do not back up configuration changes this time.
HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1