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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
interpret 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
special 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
example, to display page 5 of the SBM on volume 2 of domain dmn, enter the
following 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
following 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
examination. 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
directory, 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)
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Index for
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Alphabetical
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