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 lvsplit(1M)							 lvsplit(1M)
		 Requires Optional HP MirrorDisk/UX Software



 NAME
      lvsplit - split mirrored LVM logical volume into two logical volumes

 SYNOPSIS
      /usr/sbin/lvsplit [-A autobackup] [-s suffix] [-g PhysicalVolumeGroup]
      lv_path ...

    Remarks
      This command requires the installation of the optional HP MirrorDisk/UX
      software (not included in the standard HP-UX operating system) before
      it can be used.

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

 DESCRIPTION
      The lvsplit command splits a single- or double-mirrored logical
      volume, lv_path, into two logical volumes.  A second logical volume is
      created containing one copy of the data.	The original logical volume
      is appropriately reset as unmirrored or single-mirrored.

      If the -s option is specified, the new logical volume name has the
      form lv_pathsuffix.  If -s is not specified, suffix defaults to b, as
      in lv_pathb.

      If more than one lv_path is specified on the command line, lvsplit
      ensures that all logical volumes are brought offline together in one
      system call, ensuring predictable results among the logical volumes.
      Up to 127 logical volumes can be specified on the command line.  All
      logical volumes must belong to the same volume group, and there must
      be enough unused logical volumes remaining in the volume group to hold
      the newly split logical volumes.	A volume group can contain up to 255
      logical volumes.

      If PhysicalVolumeGroup is specified, the offline logical volumes are
      created using the mirror copies on the physical volumes contained in
      the specified physical volume group.

      Whenever a mirrored logical volume is split into two logical volumes,
      a bit map is stored that keeps track of all writes to either logical
      volume in the split pair.	 When the two logical volumes are
      subsequently merged using lvmerge, the bit map is used to decide which
      areas of the logical volumes need to be resynchronized (see
      lvmerge(1M)).  This bit map remains in existence until the merge is
      completed, until one of the logical volumes is extended, reduced, or
      split again, or until the system is rebooted.

      The new logical volume must be checked with the fsck command before it
      is mounted (see fsck(1M)).  lvsplit flushes the file system to a
      consistent state except for pipes and unlinked but open files.




 Hewlett-Packard Company	    - 1 -   HP-UX Release 11i: November 2000






 lvsplit(1M)							 lvsplit(1M)
		 Requires Optional HP MirrorDisk/UX Software



      To rejoin two split copies of a logical volume, use the lvmerge
      command (see lvmerge(1M)).

    Options and Arguments
      lvsplit recognizes the following options and arguments:

	   lv_path	       The block device path name of a logical
			       volume.	Up to 127 logical volumes in the
			       same volume group can be specified at one
			       time.

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

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

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

			       n    Do not back up configuration changes
				    this time.

	   -g PhysicalVolumeGroup
			       The offline logical volumes will be created
			       using the mirror copies on the physical
			       volumes in the specified PhysicalVolumeGroup.

	   -s suffix	       Specify the suffix to use to identify the new
			       logical volume.	The new logical volume name
			       has the form lv_pathsuffix.  If -s is
			       omitted, suffix defaults to b, as in
			       lv_pathb.

 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
      Split the mirrored logical volume /dev/vg00/lvol1 into two copies.
      Call the new logical volume /dev/vg00/lvol1backup:



 Hewlett-Packard Company	    - 2 -   HP-UX Release 11i: November 2000






 lvsplit(1M)							 lvsplit(1M)
		 Requires Optional HP MirrorDisk/UX Software



	   lvsplit -s backup /dev/vg00/lvol1

      Split the mirrored logical volume /dev/vg00/lvol1 into two copies.
      The offline logical volume will be created using the mirror copy on
      the physical volumes contain in the physical volume group pvg1.

	   lvsplit -g pvg1 /dev/vg00/lvol1

      Split an online logical volume which is currently mounted on /usr so
      that a backup can take place:

	   lvsplit /dev/vg00/lvol1
	   fsck /dev/vg00/lvol1b
	   mount /dev/vg00/lvol1b /usr.backup

	   Perform a backup operation, then:

	   umount /usr.backup
	   lvmerge /dev/vg00/lvol1b /dev/vg00/lvol1

      Split two logical volumes at the same time:

	   lvsplit /dev/vg01/database1 /dev/vg01/database2

	   Perform operation on split logical volumes, then rejoin them:

	   lvmerge /dev/vg01/database1b /dev/vg01/database1
	   lvmerge /dev/vg01/database2b /dev/vg01/database1

 WARNINGS
      After a two-way mirrored logical volume has been split once, it cannot
      be split again without merging the logical volumes using the lvmerge
      command (see lvmerge(1M)).

 SEE ALSO
      lvcreate(1M), lvextend(1M), lvmerge(1M).


















 Hewlett-Packard Company	    - 3 -   HP-UX Release 11i: November 2000