HP-UX Reference (11i v3 07/02) - 1M System Administration Commands N-Z (vol 4)

v
vgreduce(1M) vgreduce(1M)
NAME
vgreduce - remove physical volumes from an LVM volume group
SYNOPSIS
/usr/sbin/vgreduce
[-A autobackup] vg_name pv_path ...
/usr/sbin/vgreduce
[-A autobackup][-l] vg_name pv_path
/usr/sbin/vgreduce
[-A autobackup][-f] vg_name
Remarks
vgreduce cannot be performed if the volume group is activated in shared mode.
DESCRIPTION
The vgreduce command removes each physical volume specified by a pv_path argument from volume
group vg_name.
The
vgreduce command with -f option removes all missing physical volumes from the volume group.
All but one physical volume can be removed. The last physical volume must remain in the volume group so
that the logical volume driver can continue to operate. The last physical volume in the volume group can
be removed with the vgremove command (see vgremove(1M)).
Before executing vgreduce, remove all logical volumes residing on each physical volume represented by a
pv_path by executing the lvremove command (see lvremove (1M)).
Any physical volume in the pv_path list that is also a member of a physical volume group (as defined in
/etc/lvmpvg ) is also removed from the physical volume group. If the physical volume happens to be the
last one in the physical volume group, the physical volume group is also removed from the volume group.
When a physical volume in the pv_path list has multiple PV-links, the physical volume is not removed
from the volume group, until all the links to the volume are removed. When a physical volume in the
pv_path list is the primary link (in use) to a physical volume, removing the link forces LVM to switch to
the alternate link (For information on alternate links, see lvm(7)). When the pv_path removed is an
alternate link to the device, only the link is removed; the volume group and physical volume are other-
wise unchanged.
Options and Arguments
vgreduce recognizes the following options and arguments:
-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 volume group. This is
the default.
After this command executes, the vgcfgbackup command (see
vgcfgbackup(1M)) is executed for the volume group.
n Do not back up configuration changes this time.
-f vg_name Force the reduction of missing physical volumes from the specified volume group.
vgreduce obtains the name of each physical volume (PV) belonging to the volume
group. It then reads the kernel PV structures to work out which PVs are missing.
PVs which are missing will be candidates for removal.
If all the physical extents on the missing PV are free then it will be removed from the
volume group. Otherwise vgreduce will report the physical to logical extent map-
ping. For missing PVs which have extents in use, you must free up all the extents by
using the lvreduce or lvremove commands (see lvreduce(1M) and lvremove(1M))
and re-run vgreduce with the -f option. This option is most commonly used when
the vgdisplay command (see vgdisplay(1M)) shows "Cur PV" higher than "Act PV"
and all of the PVs belonging to the volume group are attached. This option only works
on PVs and not on links.
See the -l option for details on handling missing links.
-l pv_path Removes the specified pv_path/s from the lvmtab file. This task will only be per-
formed if the pv_path is currently marked as missing from the volume group. This
646 Hewlett-Packard Company 1 HP-UX 11i Version 3: February 2007