lvmerge(1M)

NAME

lvmerge — merge two LVM logical volumes into one logical volume

SYNOPSIS

/usr/sbin/lvmerge [-A autobackup] dest_lv_path src_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 number of mirrored copies of the dest_lv_path is increased by the number of copies in the src_lv_path.

Data previously contained in the dest_lv_path is resynchronized using the data in the src_lv_path. All new data on the dest_lv_path is destroyed.

Whenever a mirrored logical volume is split into two logical volumes, a bit map 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 bit map is used to decide which areas of the logical volumes need to be resynchronized. This bit map continues to exist until the merge is completed, or one of the logical volumes is extended or reduced, or the system is rebooted.

If there is no bit map available, the entire logical volume is resynchronized.

The normal usage for this command is to merge previously mirrored logical volumes that have been split using the lvsplit command (see lvsplit(1M). However, the two logical volumes are not required to have been the result of a previous lvsplit operation.

Options and Arguments

lvmerge recognizes the following options and arguments:

dest_lv_path

The block device path name of a logical volume.

src_lv_path

The block device path name of a logical volume.

-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)).

EXAMPLES

Merge /dev/vg00/lvol1b with /dev/vg00/lvol1: Data in /dev/vg00/lvol1b will be overridden by /dev/vg00/lvol1.

lvmerge /dev/vg00/lvol1b /dev/vg00/lvol1 

WARNINGS

If no bit map is found, all data on dest_lv_path is lost after the merge.

lvmerge does not check to guarantee that the allocation policy of src_lv_path is preserved after the merge.