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addvol(8)							    addvol(8)



NAME

  addvol - Adds	a volume to an existing	domain

SYNOPSIS

  /usr/sbin/addvol [-F]	[-x num_pages] [-p num_pages] special domain

OPTIONS

  -F  Ignores overlapping partition or block warnings.

  -p num_pages
      Sets the number of pages to preallocate for the bitfile metadata table
      (BMT).  The default is 0 (zero) pages. This option may be	useful if you
      are adding volumes to domains that were created prior to the release of
      Version 5.0 or with the -V3 option of the	mkfdmn command.

  -x num_pages
      Sets the number of pages by which	the bitfile metadata table (BMT)
      extent size grows.  The value must be greater than or equal to 128
      pages. The default is 128	pages. This option may be useful if you	are
      adding volumes to	domains	that were created prior	to the release of
      Version 5.0 or with the -V3 option of the	mkfdmn command.

OPERANDS

  special
      Specifies	the block device special device	name, such as
      /dev/disk/dsk1c, or the LSM volume name of the disk that you are adding
      to the domain. This command supports shorthand device names for block
      special devices. For example, if you enter dsk2g,	it will	be translated
      to /dev/disk/dsk2g.

  domain
      Specifies	the name of the	AdvFS domain.

DESCRIPTION

  A newly created domain consists of one volume, which can be a	disk or	a
  logical volume. The addvol utility enables you to increase the number	of
  volumes within an existing domain. You can add volumes immediately after
  creating a domain, or	you can	wait until the filesets	within the domain
  require additional space.

  For optimum performance, each	volume that you	add should consist of the
  entire disk (typically, partition c).	Existing data on the volume you	add
  is destroyed during the addvol procedure.





				    Caution

  Do not add a volume containing data that you want to keep.

  The addvol command checks for	potential overlapping partitions before
  adding the volume.  A	partition overlap would	occur if you could add a
  volume to a domain when a partition in it is already in use by a file	sys-
  tem, such as AdvFS or	UFS; a storage manager,	such as	LSM or a raw data-
  base;	or a swap area.	The overlap partition check prevents this error	from
  occurring.  The check	is performed on	partitions that	are active (open) and
  on partitions	that are not active (yet marked	in use).

  If you try to	add a volume that would	cause active partitions	to overlap,
  the volume is	not added and a	message	similar	to the following is
  displayed:

       Error: /dev/rdisk/dsk1g or an overlapping partition is open.
       addvol: Can't add volume	'/dev/rdisk/dsk1g' to domain 'proj_x'

  If you try to	add a volume that would	cause inactive partitions to overlap,
  the volume is	not added and a	message	similar	to the following is
  displayed.  Subsequently, you	can examine and	change the disk	label and
  then run the addvol utility to add the volume.

       Error:  Partition(s) that overlap /dev/rdisk/dsk1g
       are marked in use.
       To edit an incorrect disklabel, use the -e option with disklabel;
	for more information see the disklabel(8) reference page.
       addvol: Can't add volume	'/dev/rdisk/dsk1g' to domain 'blegga'

  Use the -F option to disable testing for overlap.

				    Caution

       Disabling the overlap check can result in extensive data	loss and
       should be used with extreme caution.

  Adding volumes to a domain does not affect the logical structure of the
  filesets within the domain. You can add a volume to an active	domain while
  its filesets are mounted and in use.

  domains created prior	to Version 5.0 or created with the -V3 option of the
  mkfdmn command that contain a	very large number of files may need added BMT
  mcells (similar to inodes in UFS).  By default, AdvFS	attempts to grow the
  BMT by 128 pages each	time additional	mcells are needed. This	may cause the
  metadata storage to become very fragmented, resulting	in a premature "out
  of disk space" error.

  You can reduce the amount of BMT metadata fragmentation for domains created
  prior	to Version 5.0 or created with the -V3 option of the mkfdmn command
  either by preallocating space	for the	BMT or by increasing the number	of
  pages	that the system	attempts to grow the BMT each time space is needed.
  Use the -p option to preallocate all the BMT space you expect	the domain to
  need.	Note that space	that is	preallocated cannot be deallocated. Use	the
  -x option to specify how many	pages the BMT should be	extended each time
  additional mcells are	needed.

  The following	table provides guidelines for BMT growth size in pages (-x
  option) and BMT preallocation	(-p option).  If your estimated	number of
  files	is greater than	those listed in	the table, keep	doubling the last
  table	entry until you	get a value that is close to your needs.





  ___________________________________________________________________
  Number of Files    BMT Growth	Size in	pages

						BMT Preallocation
						Size in	pages
  ___________________________________________________________________
  Less than 50,000   default (128)		3,600
  100,000	     256			7,200
  200,000	     512			14,400
  300,000	     768			21,600
  400,000	     1024			28,800
  800,000	     2048			57,600
  ___________________________________________________________________

  To get the maximum benefit from increasing the number	of metadata table
  extent pages,	use the	same number of pages when adding a volume with the
  addvol command as was	assigned when the domain was created with the mkfdmn
  command.

RESTRICTIONS

  You must be the root user to use this	utility.

  AdvFS	does not support a multivolume root file system. You cannot use	the
  addvol utility to expand root_domain.	 This does not apply to	cluster	root
  domains.

ERRORS

  Command execution continues after the	following warnings are displayed:

    +  addvol: Invalid value for -x addvol: Setting to minimum value of	128

       Explanation:

       You have	entered	an invalid value for the -x option.

    +  addvol: Invalid value for -p addvol: Setting to minimum value of	0.

       Explanation:

       You have	entered	an invalid value for the -p option.

EXAMPLES

   1.  The following example adds a new	volume to an active domain called
       accounts_dmn. After the new volume is added, the	balance	command	is
       run to even the distribution of files over all of the volumes in	the
       domain.
	    # addvol /dev/disk/dsk1c accounts_dmn
	    # balance accounts_dmn

       The /etc/fdmns/accounts_dmn subdirectory	now includes new entries for
       two volumes.

   2.  The following example sets up a domain for a news service that will
       handle as many as 400,000 files.	The news_dmn domain will contain two
       volumes that are	configured with	preallocated BMT and increased extent
       sizes to	accommodate the	large number of	files.
	    # mkfdmn -p	14400 -x 1024 /dev/disk/dsk1c news_dmn
	    # addvol -p	14400 -x 1024 /dev/disk/dsk2c news_dmn








FILES

  /usr/sbin/addvol
      Specifies	the command path.

  /etc/fdmns
      Contains domain names and	devices.

SEE ALSO

  Commands: advscan(8),	disklabel(8), mkfdmn(8), rmvol(8)

  Files: advfs(4), fdmns(4)