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 vgextend(1M)							vgextend(1M)




 NAME
      vgextend - extend an LVM volume group by adding physical volumes

 SYNOPSIS
      /usr/sbin/vgextend [-f] [-A autobackup] [-g pvg_name]
	   [-x extensibility] [-z sparepv] vg_name pv_path ...

    Remarks
      vgextend cannot be performed if the volume group is activated in shared
      mode.

 DESCRIPTION
      The vgextend command assigns additional physical volumes to volume
      group vg_name.  The volume group must be active.

      Volume groups are extended by adding one or more physical volumes
      specified by pv_path ...

      After the physical volumes have been successfully added to the volume
      group, the disk space they contain can be allocated to logical
      volumes.

      Before assigning an additional physical volume to a volume group,
      create the physical volume with the pvcreate command (see
      pvcreate(1M)).  Then, create the volume group with the vgcreate
      command, assigning at least one physical volume (see vgcreate(1M)).

      If, for any reason, a specified physical volume cannot be installed
      into the volume group, an error message is displayed.  However, the
      installation continues to the end of the list of physical volumes.

      When a pv_path refers to one of the physical volumes already in the
      volume group by a different pv_path name to indicate the use of a
      different controller, this new path becomes an alternate link to the
      physical volume.	 When two paths that reference the same disk are
      provided in the pv_path list, the order of the paths is important.
      The first path becomes the "primary link" to the physical volume, the
      second becomes an "alternate link" to the physical volume.  The
      primary link is the path used to access the physical volume unless the
      primary link becomes unavailable in which case LVM automatically
      switches to the alternate link to access the physical volume.
      Currently LVM supports a maximum of 8 paths to a physical volume (7
      alternates and one primary).

    Options and Arguments
      vgextend recognizes the following options and arguments:

	   pv_path	       The block device path name of a physical
			       volume.





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	   vg_name	       The path name of the volume group.

	   -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		       This option will force a volume group to be
			       extended with a physical volume which has
			       alternate block(s) already allocated, (i.e.
			       this physical volume was not initialized
			       using pvcreate -f.) This option should be
			       used with extreme caution.  If the disk is
			       being extended to a volume group with a
			       different physical extent size, the alternate
			       block(s) might be inside the user data area.
			       Potential data corruption could occur.

	   -g pvg_name	       Extend an existing physical volume group
			       while the volume group is being extended by
			       adding all the physical volumes in the
			       pv_path parameter to the physical volume
			       group specified by pvg_name.

			       If the specified physical volume group does
			       not exist, it is created, thus providing a
			       means for creating new physical volume groups
			       after the volume group has been created.
			       Another way to extend or add a physical
			       volume group is to edit the /etc/lvmpvg file
			       as described in vgcreate(1M).  See lvmpvg(4)
			       for format details.

	   -x extensibility    Set allocation permission for additional
			       physical extents on the physical volume
			       specified by pv_path.  extensibility can have
			       one of the following values:

				    y	 Allow allocation of additional
					 physical extents on the physical



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					 volume.

				    n	 Prohibit allocation of additional
					 physical extents on the physical
					 volume.  Logical volumes residing
					 on the physical volume can still be
					 accessed.

	   -z sparepv	       This option requires the installation of the
			       optional HP MirrorDisk/UX software. It allows
			       you to mark the physical volume(s) specified
			       by pv_path to be either a spare physical
			       volume or a regular, non-spare physical
			       volume.	(A spare physical volume can be used
			       to replace an existing physical volume within
			       a volume group when mirroring is in effect,
			       in the event the existing physical volume
			       fails.) sparepv can have one of the following
			       values:

				    y	 The physical volume(s) will be used
					 as spare(s). No physical extents
					 from a spare physical volume will
					 be available as part of the "free"
					 pool of extents in the volume
					 group. The spare physical volume(s)
					 will only be used in the event of
					 another physical volume within this
					 volume group becomes unavailable
					 (fails).

				    n	 The physical volume(s) will be used
					 as regular, non-spare members of
					 the volume group. This is the
					 default.

 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
      Add physical volumes /dev/dsk/c0t1d0 and /dev/dsk/c0t2d0 to volume
      group /dev/vg03:

	   vgextend /dev/vg03 /dev/dsk/c0t1d0 /dev/dsk/c0t2d0




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 vgextend(1M)							vgextend(1M)




      Extend physical volume group PVG0 while adding physical volumes
      /dev/dsk/c0t3d0 and /dev/dsk/c0t4d0 to volume group /dev/vg03:

	   vgextend -g PVG0 /dev/vg03 /dev/dsk/c0t3d0 /dev/dsk/c0t4d0

      Add an alternate link to one of the physical volumes in the volume
      group where /dev/dsk/c0t4d0 and /dev/dsk/c1t4d0 refer to the same
      physical volume (referenced via different controllers), and the volume
      group already contains /dev/dsk/c0t4d0.  /dev/dsk/c0t4d0 remains the
      primary link (in use) and /dev/dsk/c1t4d0 becomes the alternate link.

	   vgextend  /dev/vg03 /dev/dsk/c1t4d0

      Add a spare physical volume to a volume group:

	   vgextend  -z y /dev/vg03 /dev/dsk/c2t4d0

 WARNINGS
      The new physical volume which has been added to the volume group could
      potentially have a different block size compared to physical volumes
      already in the volume group.

      If a logical volume is created on two or more physical volumes which
      have a different block size, it is not possible to use such logical
      volume for file system purposes. See extendfs(1M).

      For example, when a logical volume contains physical volumes that all
      have 1k block size, and then it is extended to contain a physical
      volume with 2k block size, then the block size of the volume group is
      increased to 2k.

 ADDITIONAL WARNINGS
      Starting at 10.20, the vgextend command is supporting additional EMC
      Symmetrix disk product functionality (see vgchgid(1M)).  The vgextend
      command will be enforcing a new rule such that a physical device, to
      be extended to a volume group, must have the same EMC Symmetrix
      attributes as the physical volumes already in the volume group.
      Clearly this checking only applies if the disks involved (those
      already in the volume group and those being added) in the operation
      are EMC Symmetrix.  Should the command find an incompatibility, a
      message of the following type will be produced:

	   "Attempt to mix incompatible EMC Symmetrix disk types failed.
	   Volume group contains standard disks, but physical volume
	   /dev/dsk/cxtxdx contains EMC BCV DISK.  Please consult the EMC
	   Symmetrix documentation, if applicable".

    Cross-Cabinet Volume Group Warnings
      On multi-cabinet V-Class systems, it is possible to create a volume
      group using physical volumes that are physically attached to different
      cabinets.	 However, due to limitations in the HP-UX boot sequence,



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      such a cross-cabinet volume group cannot contain root, boot, swap, or
      dump logical volumes.  If the volume group vg_name contains a root,
      boot, swap, or dump logical volume, and by adding the physical
      volume(s) specified by pv_path to the volume group it would become
      cross-cabinet, then vgextend will fail.

 SEE ALSO
      pvchange(1M), pvcreate(1M), vgchange(1M), vgcreate(1M), vgdisplay(1M).














































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