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vsbmpg(8)							    vsbmpg(8)



NAME

  vsbmpg - Display a page from a Storage Bitmap	(SBM) file

SYNOPSIS

  /sbin/advfs/vsbmpg [-v] sbm_id | domain_id

  /sbin/advfs/vsbmpg sbm_id page [entry]

  /sbin/advfs/vsbmpg sbm_id -a

  /sbin/advfs/vsbmpg sbm_id -i index

  /sbin/advfs/vsbmpg sbm_id -B block

  /sbin/advfs/vsbmpg volume_id -b block

  /sbin/advfs/vsbmpg volume_id -d dump_file

OPTIONS

  -a  Display all the pages of the SBM file.

  -B block
      Display the portion of the SMB that maps the specified block.

  -b block
      Specifies	a starting block for the part of an AdvFS volume that you
      want to format as	an SBM page.

  -d dump_file
      Specifies	the name of a file that	contains the output of this utility.

  -i index
      Display the SBM word specified by	the index.

  -v  Check the	checksum on each page of the SBM.

OPERANDS

  sbm_id
      Specifies	an SMB file using the following	format:

      volume_id	| [-F] dump_file
	  The dump_file	parameter is a previously-saved	copy of	the fileset's
	  SBM file.  You can use the -F	option to force	the utility to inter-
	  pret the dump_file parameter as a file name if it has	the same name
	  as a domain name.

  domain_id
      Specifies	an AdvFS file domain using the following format:

      [-r] [-D]	domain
	  By default, the utility opens	all volumes using block	device spe-
	  cial files. Specify the -r option to operate on the raw device
	  (character device special file) of the domain	instead	of the block
	  device. Specify the [-D] option to force the utility to interpret
	  the name you supply in the domain argument as	a domain name.

  volume_id
      Specifies	an AdvFS volume	using the following format:

      [-V] volume | domain_id volume_index
	  Specify the -V option	to force the utility to	interpret the name
	  you supply in	the volume argument as a volume	name. The volume name
	  argument also	can be a full or partial path name, for	example
	  /dev/disk/dsk12a or dsk12a. Specifying a partial path	name always
	  opens	the character device special file.

	  Alternatively, specify the volume by using arguments for its
	  domain, domain_id, and its volume index number, volume_index.

  page
      Specifies	the file page number of	the SBM	file.

  entry
      Specifies	the index of the SBM word on the page.

DESCRIPTION

  Storage Bitmaps (SBMs) are used by the AdvFS to track	free and allocated
  disk space of	AdvFS volumes.	Each volume in an AdvFS	domain has one SBM
  file.	The vsbmpg utility displays pages of a SBM file.

  SBM Page Summaries


  When you specify just	a domain_id or a volume_id, a summary of the SBMs for
  the domain or	volume is displayed.

  Displaying an	SBM File Page


  The utility can display a whole page of map entries or one particular	map
  entry	on a page.  The	utility	also can display the entire SBM.  For exam-
  ple, to display page 5 of the	SBM on volume 2	of domain dmn, enter the fol-
  lowing command:

       # /sbin/advfs/vsbmpg dmn	2 5

  To display page 5 of the SBM on volume /dev/disk/dsk5c, enter	the following
  command:

       # /sbin/advfs/vsbmpg dsk5c 5

  To display the entire	SBM, from page zero to the last	page, use the -a
  option in a command similar to the following:

       # /sbin/advfs/vsbmpg /dev/disk/dsk5c -a










  Displaying One SBM Entry


  To use the utility to	examine	just one SBM map entry,	use the	-i option.
  The following	example	shows how to display index 456 from /dev/disk/dsk5a:

       # /sbin/advfs/vsbmpg dsk5a -i 456

  To use the utility to	examine	just one SBM map entry on a page, enter	the
  volume, page and entry.  The following example shows how to display SBM map
  entry	7 from page 3 of /dev/disk/dsk5a:

       # /sbin/advfs/vsbmpg dsk5a 3 7

  To use the utility to	determine whether a block on a volume is in use,
  employ the -B	option.	 The following example shows how to display block 987
  on volume 3 of domain	dmn and	options	the bit	that contains the requested
  block	with a caret (^) character:

       # /sbin/advfs/vsbmpg dmn	3 - 987

  Displaying Corrupted Volumes


  When volumes in a domain are corrupted, you can display pages	from them,
  formatting them as SBM pages.	 For example, to display block 96 on disk
  rz2b formatted as a SBM page,	enter the following command:

       # /sbin/advfs/vsbmpg rz2b -b 96

  You can also attempt to display a disk block on a volume of a	domain,	by
  specifying the domain	name and the volume index, although it may not
  display if the BMT for the volume is corrupt.	 For example, to attempt to
  display block	96 of volume 2 in a domain named domain_1, enter the follow-
  ing command:

       # /sbin/advfs/vsbmpg domain_1 2 -b 96

  Saving or Displaying an SBM File


  The utility can read an SBM file and dump it to a file for later examina-
  tion.	 For example to	extract	and save the SBM file from the first AdvFS
  volume in domain_1 to	a file named save_file in the current working direc-
  tory,	enter the following command:

       # /sbin/advfs/vsbmpg domain_1 1 -d save_file

  Subsequently,	to view	page 4 of the file saved in the	previous example,
  enter	the following command:

       # /sbin/advfs/vsbmpg save_file 4

NOTES

  An active domain, which is a domain with one or more of its filesets
  mounted, has all of its volumes opened using block device special files.
  These	devices	cannot be opened a second time without first being unmounted.
  However, the character device	special	files for the volumes can be opened
  more than once while still mounted.

  It can be misleading to use this utility on a	domain with mounted filesets
  because the utility does not synchronize its read requests with AdvFS	file
  domain read and write	requests.

  For example, the AdvFS can be	writing	to the disk as the utility is reading
  from the disk.  Therefore, when you run the utility, metadata	may not	have
  been flushed in time for the utility to read it and consecutive reads	of
  the same file	page may return	unpredictable or contradictory results.	[The
  domain is not	harmed.]

  To avoid this	problem, unmount all the fileset in the	domain before using
  this utility.

RESTRICTIONS

  The utility can fail to open a block device, even when there are no
  filesets mounted for the domain and the AdvFS	daemon,	advfsd is running.
  The daemon, as it runs, activates the	domain for a brief time.  If the
  vsbmpg utility fails in this situation, run it again.

  You must be the root user to use this	command.

EXIT STATUS

  The utility returns a	0 (zero) on success, otherwise it returns a nonzero
  value	and an error diagnostic.

FILES

  /sbin/advfs/vsbmpg
      Specifies	the command path.

  /etc/fdmns/domain_name
      Specifies	the volumes in the domain.

SEE ALSO

  Commands: vfilepg(8),	nvfragpg(8), nvlogpg(8), nvtagpg(8), vbmtpg(8)