lvmerge(1M)lvmerge(1M)NAMElvmerge - merge two LVM logical volumes into one logical volume
SYNOPSIS
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.
DESCRIPTION
The 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.
By default, completes after all the extents are resynchronized. When
run with the option, if there is no bitmap (see below), returns without
resynchronizing the remaining logical volume. Using the option may
affect data high availability as extents may remain stale. Use or to
synchronize the mirrors.
The normal usage for this command is to merge previously mirrored logi‐
cal volumes that have been split using the command. However, the two
logical volumes are not required to have been the result of a previous
operation.
NOTE: When a mirrored logical volume of a non-shared volume group is
split into two logical volumes using 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 cre‐
ated. When the two logical volumes are subsequently merged using the
bitmap is used to decide which areas of copy_lv_path need to be resyn‐
chronized 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
option is ignored.
Options and Arguments
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.
Set automatic backup for this invocation of this command.
autobackup can have one of the following val‐
ues:
Automatically back up configuration changes
made to the logical volume.
This is the default.
After this command executes, the com‐
mand (see vgcfgbackup(1M)) is executed
for the volume group to which the logi‐
cal volume belongs.
Do not back up configuration changes this
time.
If there is no bitmap, do not synchronize the
new mirrors in the master_lv_path after the
merge. Using the option may affect data high
availability as extents may remain stale. Use
or to synchronize the mirrors.
Shared Volume Group Considerations
For volume group version 1.0 and 2.0, cannot be used if the volume
group is activated in shared mode. For volume groups version 2.1 (or
higher), can be performed when activated in either shared, exclusive,
or standalone mode.
Note that the daemon must be running on all the nodes sharing a volume
group activated in shared mode. See lvmpud(1M).
When a node wants to share the volume group, the user must first exe‐
cute a if logical volumes were merged at the time the volume group was
not activated on that node.
LVM shared mode is currently only available in Serviceguard clusters.
EXTERNAL INFLUENCES
Environment Variables
determines the language in which messages are displayed.
If 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 with Data in will be overwritten by and will be removed.
Merge with Data in will be overwritten by and will be removed. If the
bitmap does not exist, then mark all extents associated with as stale
and complete without resynchronizing.
WARNINGS
does not check to guarantee that the allocation policy of mas‐
ter_lv_path is preserved after the merge.
SEE ALSOlvcreate(1M), lvextend(1M), lvmpud(1M), lvsplit(1M), lvsync(1M),
vgsync(1M).
Requires Optional HP MirrorDisk/UX Software lvmerge(1M)
