The Analyze/Disk_Structure utility checks the readability and
validity of Files-11 Structure Levels 1, 2, and 5 disk volumes,
and reports errors and inconsistencies. You can detect most
classes of errors by invoking the utility once and using its
defaults.
Format
ANALYZE/DISK_STRUCTURE device-name:[/qualifier]
1 – Parameter
device-name
Specifies the disk volume or volume set to be verified. If you
specify a volume set, all volumes of the volume set must be
mounted as Files-11 volumes. For information about the Mount
utility, refer to the OpenVMS System Management Utilities
Reference Manual.
2 – Qualifiers
Qualifier Description
/CONFIRM Determines whether ANALYZE/DISK_STRUCTURE
prompts you to confirm each repair
/EXTENTS Reports on the fragmentation of free space
on a volume
/HOMEBLOCKS Erases damaged home blocks on an initialized
volume
/LIST[=filespec] Determines whether ANALYZE/DISK_STRUCTURE
produces a listing of the index file
/LOCK_VOLUME (Alpha/I64 only) Prevents updates to a
volume while you are analyzing it
/OUTPUT[=filespec] Specifies the output file to which
ANALYZE/DISK_STRUCTURE writes the disk
structure errors
/READ_CHECK Determines whether ANALYZE/DISK_STRUCTURE
performs a read check of all allocated blocks
on the specified disk
/RECORD_ Determines whether ANALYZE/DISK_STRUCTURE
ATTRIBUTES repairs files containing erroneous settings
in the record attributes section of their
associated file attribute block (FAT)
/REPAIR Determines whether ANALYZE/DISK_STRUCTURE
repairs errors that are detected in the file
structure of the specified device
/SHADOW Causes the entire contents of a shadow set or
a specified range of blocks in a shadow set to
be checked for discrepancies.
/STATISTICS Produces statistical information about the
volume under verification and creates a
file, STATS.DAT, which contains per-volume
statistics
/USAGE[=filespec] Specifies that a disk usage accounting file
should be produced, in addition to the other
specified functions of ANALYZE/DISK_STRUCTURE
3 /CONFIRM
Determines whether the Analyze/Disk_Structure utility prompts you
to confirm each repair. If you respond with Y or YES, the utility
performs the repair. Otherwise, the repair is not performed.
Format
/CONFIRM
/NOCONFIRM
4 /EXTENTS
Reports on the fragmentation of free space on the volume. By
default, the only output is the number of extents of free space
and the total number of free blocks. You must specify /LARGEST
or /REQUIRED to obtain additional details.
Format
/EXTENTS
4.1 – Qualifiers
4.1.1 /LARGEST
Displays a list of block counts for the n largest extents of
free space on the volume in descending size order. The default
for n is 10. The qualifier is ignored if you specify zero or a
negative number.
The list is also saved in the DCL symbol ANALYZE$LARGEST_EXTENTS
(as a comma-separated list of decimal values). The symbol is set
to an empty string if there's no free space on the disk.
There's no upper limit on n, but if the DCL symbol would exceed
1024 characters, the number of extents in the symbol will be
reduced to ensure the symbol is no more than 1024 characters.
Format
/LARGEST[=n]
4.1.2 /LOCK_VOLUME
The volume is locked against allocation while the data is being
collected.
Format
/LOCK_VOLUME (default)
/NOLOCK_VOLUME
4.1.3 /OUTPUT
Specifies the output file to which the ANALYZE/DISK_STRUCTURE
utility is to write the fragmentation report. If you omit the
qualifier or the entire filename, SYS$OUTPUT is used. The
default filename is ANALYZE$EXTENTS.LIS.
Format
/OUTPUT[=filespec]
/NOOUTPUT
4.1.4 /REQUIRED
Displays the number of extents are needed to satisfy an allocation
request of n blocks (starting with the largest extent and working
down). There is no default for n. If you specify zero or a negative
number, the qualifier is ignored
The result is also saved in the DCL symbol ANALYZE$REQUIRED_EXTENTS.
The symbol is set to an empty string if there is insufficient space
on the disk to satisfy the allocation request.
Format
/REQUIRED=n
5 /HOMEBLOCKS
Erases home blocks from a volume whose home blocks were not
deleted during previous initialization operations.
Format
/HOMEBLOCKS
6 /LIST
Determines whether the Analyze/Disk_Structure utility produces a
listing of the index file.
Format
/LIST[=filespec]
/NOLIST
7 /LOCK_VOLUME
Prevents updates to a volume while you are analyzing it.
Format
/LOCK_VOLUME
/NOLOCK_VOLUME
8 /OUTPUT
Specifies the output file to which the Analyze/Disk_Structure
utility is to write the disk structure errors.
Format
/OUTPUT[=filespec]
/NOOUTPUT[=filespec]
9 /READ_CHECK
Determines whether the Analyze/Disk_Structure utility performs
a read check of all allocated blocks on the specified disk.
When the Analyze/Disk_Structure utility performs a read check,
it reads the disk twice; this ensures that it reads the disk
correctly. The default is /NOREAD_CHECK.
Format
/READ_CHECK
/NOREAD_CHECK
10 /RECORD_ATTRIBUTES
Determines whether the Analyze/Disk_Structure utility repairs
files containing erroneous settings in the record attributes
section of their associated file attribute block (FAT).
Format
/RECORD_ATTRIBUTES
11 /REPAIR
Determines whether the Analyze/Disk_Structure utility repairs
errors that are detected in the file structure of the specified
device.
Format
/REPAIR
/NOREPAIR
12 /SHADOW
Examines the entire contents of a shadow set or a specified range
of blocks in a shadow set for discrepancies.
Format
/SHADOW
12.1 – Qualifiers
12.1.1 /BLOCKS
/BLOCKS={(START:n, COUNT:x, END:y,) FILE_SYSTEM, ALL}
Directs the system to compare only the range specified. The
options are the following:
START:n Number of the first block to be analyzed. The default
is the first block.
COUNT:x Number of blocks to be analyzed. You can use this
option in combination with or instead of the END
option.
END:y Number of the last block to be analyzed. The default
is the last block of the volume.
FILE_ Blocks currently in use by valid files on the disk.
SYSTEM This is the default.
ALL All blocks on the disk.
You can specify START,END,COUNT and either ALL or FILE_SYSTEM.
For example, if you specify /BLOCKS=(START,END,COUNT:100,ALL),
the software checks the first 100 blocks on the disk, whether or
not the file system is using them.
If you specify /BLOCKS=(START,END,COUNT:100,FILE_SYSTEM), the
software checks only those blocks that valid files on the disk
are using.
12.1.2 /BRIEF
Displays only the logical block number (LBN) if the data in
a block is found to be different. Without this qualifier, if
differences exist for an LBN, the hexadecimal data of that block
will be displayed for each member.
12.1.3 /IGNORE
/IGNORE
[NO]IGNORE
Ignore "special" files that are likely to have some blocks with
different data. These differences, however, are not unusual and
can, therefore, be ignored.
Other special files are the following:
SWAPFILE*.*
PAGEFILE*.*
SYSDUMP.DMP
SYS$ERRLOG.DMP
IGNORE is the default.
12.1.4 /OUTPUT
/OUTPUT=filename
Output the information to the specified file.
12.1.5 /STATISTICS
Display only the file header and footer. The best use of this
qualifier is with the /OUTPUT qualifier.
13 /STATISTICS
Produces statistical information about the volume under
verification and creates a file, STATS.DAT, which contains per-
volume statistics.
Format
/STATISTICS
14 /USAGE
Specifies that a disk usage accounting file should be produced,
in addition to the other specified functions of the Analyze/Disk_
Structure utility.
Format
/USAGE[=filespec]