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 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. 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 mapping. For missing PVs which have extents in use, you must free up all the extents by using lvreduce or lvremove and re-run vgreduce with the -f option. This option is most commonly used when the vgdisplay 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.

See the -l option for details on handling missing 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 vgimport command place too many links beyond the max limit allowed in the lvmtab file. Currently the max limit is 8 paths to a PV (seven alternates and one primary). In this situation invoking the command without the -f option will not resolve the condition because the path is not attached to the volume group. Similarly the condition would not be overcome by invoking with the -f option as this works on PVs rather than links.

pv_path

The block device path name of a physical volume.

vg_name

The path name of the volume group.

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

Remove physical volume /dev/dsk/c0t1d0 from volume group /dev/vg01:

vgreduce /dev/vg01 /dev/dsk/c0t1d0 

Force reduction of missing PVs from volume group: vg01

vgreduce -f /dev/vg01 

The following messages will appear after missing PVs has been removed successfully:

PV with key 0 successfully deleted from vg /dev/vg01
Repair done, please do the following steps.....:
1. Save /etc/lvmtab to another file.
2. Remove /etc/lvmtab.
3. Use vgscan -v to recreate /etc/lvmtab.
4. NOW use vgcfgbackup to save the LVM setup.

Remove the physical volume from the vg01 volume group when it is still in the lvmtab file but is currently marked as missing from the volume group:

vgreduce -l /dev/vg01 

vgreduce(1M)

Technical documentation

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