HP-UX Reference (11i v3 07/02) - 1M System Administration Commands A-M (vol 3)

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] 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.
lvmerge cannot be performed if the volume group is activated in shared mode.
DESCRIPTION
The lvmerge command merges two logical volumes of the same size. The copy_lv_path is added as a mir-
rored copy of master_lv_path and only the master_lv_path logical volume is retained. The number of mir-
rored copies of the master_lv_path is increased by the number of copies in the copy_lv_path.
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.
lvmerge blocks until all the extents are resynchronized.
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: Whenever a mirrored logical volume 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. 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.
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.
EXTERNAL INFLUENCES
Environment Variables
LANG determines the language in which messages are displayed.
If 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)).
484 Hewlett-Packard Company − 1 − HP-UX 11i Version 3: February 2007