vgreduce(1M)															      vgreduce(1M)

NAME

       vgreduce - remove physical volumes from an LVM volume group

SYNOPSIS

       autobackup] vg_name pv_path ...

       autobackup] vg_name pv_path

       autobackup] vg_name

DESCRIPTION

       The command removes each physical volume specified by a pv_path argument from volume group vg_name.

       The command with 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 command (see vgremove(1M)).

       Before executing remove all logical volumes residing on each physical volume represented by a pv_path by executing the command  (see  lvre-
       move(1M)).

       Any  physical  volume in the pv_path list that is also a member of a physical volume group (as defined in 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 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 (in use) to a physical volume,  removing	the  link  forces  LVM	to
       switch  to  the	(For information on alternate links, see lvm(7)).  When the pv_path removed is an to the device, only the link is removed;
       the volume group and physical volume are otherwise unchanged.

       When a physical volume is added into volume groups version 2.0 or higher, the number of physical extents available on this device  will	be
       added  into  of	the  volume group (see vgdisplay(1M)).	If the size of physical volume is such that would exceed the VG Max Extents of the
       volume group, the number of physical extents available on this device will be reduced accordingly (see vgextend(1M)).  If a subsequent on a
       different  physical volume, frees up space, then the number of extents allocated to the partial physical volume is automatically increased.
       Under these circumstances the command will display the old and the new values for the count for this partial physical  volume  (see  pvdis-
       play(1M)).

   Options and Arguments
       recognizes the following options and arguments:

	      Set automatic backup for this invocation of this command.
			     autobackup can have one of the following values:

			     Automatically back up configuration changes made to the
				    volume group.  This is the default.

				    After this command executes, the command (see vgcfgbackup(1M)) is executed for the volume group.

			     Do not back up configuration changes this time.

	      Force the reduction of missing physical volumes from the specified
			     volume group.  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 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 the or commands (see lvreduce(1M) and lvremove(1M)) and re-run with the option.  This option is most
			     commonly  used  when the 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 option for details on handling missing links.

	      Removes the specified
			     pv_path/s from the or 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 or the command place too many links beyond
			     the max limit allowed in the or file.  Currently the max limit is 8 paths to a PV (seven alternates and one primary).
			     In  this  situation,  invoking  the command without the option will not resolve the condition because the path is not
			     attached to the volume group.  Similarly, this condition can not be overcome by invoking with the option, as the same
			     works on physical volumes rather than the links.

	      pv_path	     The block device path name of a physical volume.

	      vg_name	     The path name of the volume group.

   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).

       In the case a PV alternate link is reduced, is updated only on the server node.	In the case a PV is reduced, all  the  PV  device  special
       files are removed from on all the nodes sharing the volume group.

       When  a	node  wants to share the volume group, the user must first execute a if physical volumes were removed 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

       Remove physical volume from volume group

       Force, reduction of missing PVs from volume group:

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

	      PV with key 0 successfully deleted from vg

	      Repair done, please do the following steps.....:

	      1.  Save or to another file.

	      2.  Remove or

	      3.  Use to recreate or

	      4.  NOW use to save the LVM setup.

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

SEE ALSO

       lvmpud(1M), vgchange(1M), vgcreate(1M), vgdisplay(1M), vgextend(1M), intro(7), lvm(7).

																      vgreduce(1M)