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 vgreduce(1M)                                                   vgreduce(1M)

 NAME    [Toc]    [Back]
      vgreduce - remove physical volumes from an LVM volume group

 SYNOPSIS    [Toc]    [Back]
      /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    [Toc]    [Back]
      vgreduce cannot be performed if the volume group is activated in shared

 DESCRIPTION    [Toc]    [Back]
      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

      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    [Toc]    [Back]
      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

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 vgreduce(1M)                                                   vgreduce(1M)

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

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

                          n    Do not back up configuration changes this

           -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 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 (7 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.

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 vgreduce(1M)                                                   vgreduce(1M)

           vg_name        The path name of the volume group.

    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    [Toc]    [Back]
      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

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

           vgreduce -l /dev/vg01

      The following messages will appear after missing PVS has been removed

                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(1M) to save the LVM setup.

 SEE ALSO    [Toc]    [Back]
      vgchange(1M), vgcreate(1M), vgdisplay(1M), vgextend(1M).

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[ Back ]
 Similar pages
Name OS Title
vgextend HP-UX extend an LVM volume group by adding physical volumes
pvdisplay HP-UX display information about physical volumes within LVM volume group
lvremove HP-UX remove one or more logical volumes from LVM volume group
pvmove HP-UX move allocated physical extents from one LVM physical volume to other physical volumes
vgscan HP-UX scan physical volumes for LVM volume groups
pvchange HP-UX change characteristics and access path of physical volume in LVM volume group
pvck HP-UX check or repair a physical volume in LVM volume group
pvcreate HP-UX create physical volume for use in LVM volume group
pvremove HP-UX remove LVM data structure from a physical volume
vgexport HP-UX export an LVM volume group and its associated logical volumes
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