HP-UX Reference (11i v2 03/08) - 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 volume 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 lvremove (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 to access the physical volume. When the pv_path removed is an alternate link to
the device, only the link is removed; the volume group and physical volume are otherwise 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 reduction of missing physical volume(s) in a given volume group. This option
does not require a physical volume (PV) to be supplied on the command line.
vgreduce obtains the name of each physical volume (PV) belonging to the volume
group from the file /etc/lvmtab. It then reads the LVM structures from each PV
and compares these with that held by the kernel 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 mapping. For missing PVs,
which have extents in use, you must free up all the extents by using lvreduce (1M)
or lvremove (1M) and re-run vgreduce with the -f option. This option is most
commonly used when the vgdisplay (1M) command 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.
-l pv_path This option removes the specified pv_path/s from the lvmtab file. This task will
only be performed if the pv_path is currently marked as missing from the volume
group. This option was mainly designed for the problem where the vgscan or the
HP-UX 11i Version 2: August 2003 − 1 − Hewlett-Packard Company Section 1M−−873