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mkfdmn(8)							    mkfdmn(8)



NAME

  mkfdmn - Creates a new AdvFS domain

SYNOPSIS

  /sbin/mkfdmn [-F] [-l	num_pages] [-o]	[-p num_pages] [-r] [-x	num_pages]
  [-V3	| -V4] special domain

OPTIONS

  -F  Ignores overlapping partition or block warnings.

  -l num_pages
      Sets the number of pages in the log file.	 AdvFS rounds this number up
      to a multiple of four.

  -o  Allows reuse of an existing domain name. It destroys the existing
      domain and creates a new domain with the existing	domain name.

  -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
      have chosen the -V3 option; it is	not applicable for domains created
      with V4.

  -r  Specifies	the domain as the local	root domain. This prevents multiple
      volumes in the root domain.  AdvFS supports only one volume in the
      local root domain. This does not apply to	the cluster root domain.

  -V3 |	-V4
      If you specify -V3, creates an AdvFS domain that uses the	on-disk	for-
      mats employed by AdvFS prior to the release of OS	Version	5.0; that is,
      creates a	domain with a domain version number (DVN) of 3.	 If you
      specify -V4, creates an AdvFS domain that	uses the on-disk formats
      employed by AdvFS	starting with the release of OS	Version	5.0; that is,
      creates a	domain with a DVN of 4.	 If neither option is specified, the
      default action is	to use the DVN 4 on-disk formats for the domain.

  -x num_pages
      Sets the number of pages by which	the 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 have chosen the -V3 option; it is not
      applicable for domains created with the -V4 option

OPERANDS

  special
      Specifies	the block special device name, such as /dev/disk/dsk1c,	or
      the LSM volume name of the initial volume	that you use to	create the
      domain.  This command supports short hand	names for block	special	dev-
      ices. For	example, if you	enter dsk2g, it	will be	translated to
      /dev/disk/dsk2g.

  domain
      Specifies	the name of the	domain.




DESCRIPTION

  The mkfdmn command creates a domain, which is	a logical construct contain-
  ing both physical volumes (disks or disk partitions) and filesets. When you
  create a domain, you must specify one	volume.	This can be an LSM volume.

  The minimum size of an AdvFS domain depends to some degree on	the size of
  the disk or logical volume on	which it is created. It	is generally not pos-
  sible	to create a domain smaller than	6 or 7 megabytes. If you attempt to
  create a domain on a disk or logical volume that is too small, AdvFS will
  display errors like the following:

       bs_disk_init: disk is too small
       mkfdmn: domain init error ENO_MORE_BLKS (-1040)
       mkfdmn: can't create new	domain 'small_domain'

  If you try to	add a volume whose partitions would overlap any	volumes	used
  by another file system (as indicated on the disk label), including UFS,
  AdvFS, and LSM, the mkfdmn command displays a	message	asking if you want to
  continue:

       Partition(s) which overlap /dev/rdisk/dsk10a are	marked in use.
       If you continue with the	operation you can
       possibly	destroy	existing data.
       CONTINUE? [y/n] y

  Use the -F option to disable testing for overlap.

				    Caution

       Existing	data on	the volume you assign to a new domain is destroyed
       when the	domain is created.

  The mkfdmn command does not create a file system that	you can	mount.	In
  order	to mount an AdvFS file system, the domain must contain one or more
  filesets. Run	the mkfset command to create at	least one fileset within the
  new domain. You can access the domain	as soon	as you mount one or more
  filesets. For	more information about creating	filesets, see mkfset(8).

  To remove a domain, dismount all filesets in the domain you want to remove.
  Then use the rmfdmn command to remove	the domain.  Using the rmfdmn command
  is preferable	to removing the	directory defining a domain because the	com-
  mand changes the disk	label information to indicate that the partition is
  no longer in use by AdvFS.

  If the /etc/fdmns directory is lost or the volumes of	a domain are moved to
  a different system, you can use the advscan command to re-create a domain.
  See advscan(8).

  Domains created with the -V3 option 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 file domains
  created with the -V3 option 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 file domain to need. Note that space that is preallo-
  cated	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) that you may want to use if	you
  are creating domains with the	-V3 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
  ____________________________________________________________________

NOTES

  If you make a	domain using the -p or -x options to increase the BMT extent
  allocations, you must	use the	same option with the same number of pages
  when you add a volume	to the file domain with	the addvol command. See
  addvol(8) for	information about adding a volume to a file domain.

  Use a	value in the -x	num_pages argument that	maintains the following	rela-
  tionship between the BMT extent size (the number of pages for	the -x param-
  eter)	and the	log file size (the number of pages for the -l parameter):

       BMT extent size <= (log file size * 8184) / 4

  It takes about one minute to process 5000 BMT	extent size pages with the -x
  option.  A process that initiates a BMT extent size operation	must take
  into account that very large values for -x will take a long time to com-
  plete.

RESTRICTIONS

  You must be the root user to use this	command.

  All white space characters (tab, line	feed, space, and so on)	and the	/ # :
  * ? characters are invalid for domain	names.

ERRORS

  Command execution continues after the	following warnings are displayed:

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

       Explanation:

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

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

       Explanation:

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





EXAMPLES

  The following	example	creates	the accounts_dmn file domain with the special
  device /dev/disk/dsk1c as the	initial	volume:

       # mkfdmn	/dev/disk/dsk1c	accounts_dmn

  Until	you create and mount a fileset for the accounts_dmn domain, you	can-
  not access the file system.

FILES

  /etc/fdmns
      Contains	domain names and devices.

SEE ALSO

  Commands: addvol(8), advscan(8), mkfset(8), mount(8),	rmfdmn(8),
  showfdmn(8)

  Files: fdmns(4)