HP OpenVMS Systems Documentation
HP OpenVMS System Management Utilities Reference Manual
Changes the width of Buffered I/O and Direct I/O fields in a report from 8 to 10 characters.
The /WIDE qualifier corrects a problem that users have had with ACCOUNTING reports: the Buffered I/O and Direct I/O fields were too small and displayed asterisks (*) when numbers exceeded 8 characters.
$ ANALYZE/DISK_STRUCTURE DBA1:
When you issue this command, ANALYZE/DISK_STRUCTURE runs through eight stages of data collection, then, by default, prints a list of all errors and lost files to your terminal. One type of problem that ANALYZE/DISK_STRUCTURE locates is an invalid directory backlink; a backlink is a pointer to the directory in which a file resides. If your disk has a file with an invalid directory backlink, ANALYZE/DISK_STRUCTURE displays the following message and the file specification to which the error applies:
%VERIFY-I-BACKLINK, incorrect directory back link [SYSEXE]SYSBOOT.EXE;1
$ ANALYZE/DISK_STRUCTURE DBA1:/REPAIR
HP recommends using a colon (:) after device names in commands.
To select which errors ANALYZE/DISK_STRUCTURE repairs, use both the /REPAIR and /CONFIRM qualifiers:
$ ANALYZE/DISK_STRUCTURE DBA1:/REPAIR/CONFIRM
When you issue this command, ANALYZE/DISK_STRUCTURE displays a description of each error and prompts you for confirmation before making a repair. For example, the previous command might produce the following messages and prompts:
%VERIFY-I-BACKLINK, incorrect directory back link [SYS0]SYSMAINT.DIR;1
Repair this error? (Y or N): Y
%VERIFY-I-BACKLINK, incorrect directory back link [SYSEXE]SYSBOOT.EXE;1]
Repair this error? (Y or N): N
Consider running ANALYZE/DISK_STRUCTURE twice for each volume. First, invoke the utility to report all errors. Evaluate the errors and decide on an appropriate action. Then invoke the utility again with the /REPAIR qualifier to repair all errors, or with the /REPAIR and /CONFIRM qualifiers to repair selected errors.
For message descriptions, use the online Help Message (MSGHLP) utility or see the OpenVMS system messages documentation.
A lost file is a file that is not linked to a directory. Under normal circumstances, files do not become lost. However, files occasionally become lost because of disk corruption, hardware problems, or user error. For example, in cleaning up files and directories, you might inadvertently delete directories that still point to files. When you delete a directory file (a file with the file type .DIR) without first deleting its subordinate files, the files referred to by that directory become lost files. Though lost, these files remain on the disk and consume space.
For example, to report and repair all errors and lost files found on the device DDA0, issue the following command:
$ ANALYZE/DISK_STRUCTURE/REPAIR/CONFIRM DDA0:
If it discovers lost files on your disk, ANALYZE/DISK_STRUCTURE issues messages similar to those that follow:
%VERIFY-W-LOSTHEADER, file (16,1,1) X.X;1 not found in a directory %VERIFY-W-LOSTHEADER, file (17,1,1) Y.Y;1 not found in a directory %VERIFY-W-LOSTHEADER, file (18,1,1) Z.Z;1 not found in a directory %VERIFY-W-LOSTHEADER, file (19,1,1) X.X;2 not found in a directory %VERIFY-W-LOSTHEADER, file (20,1,1) Y.Y;2 not found in a directory %VERIFY-W-LOSTHEADER, file (21,1,1) Z.;1 not found in a directory %VERIFY-W-LOSTHEADER, file (22,1,1) Z.;2 not found in a directory %VERIFY-W-LOSTHEADER, file (23,1,1) LOGIN.COM;163 not found in a directory %VERIFY-W-LOSTHEADER, file (24,1,1) MANYACL.COM;1 not found in a directory
All lost files in this example are automatically moved to SYSLOST.DIR.
When you initialize a volume, the initialize operation might not erase old home blocks. These are blocks that were created by previous initialize operations. If a volume that has old home blocks is damaged, you may not be able to recover the volume without erasing the blocks.
You can erase old home blocks manually by using the /HOMEBLOCKS qualifier on the ANALYZE/DISK_STRUCTURE command as follows:
Note that this operation can take up to 30 minutes to complete.
By default, the Analyze/Disk_Structure utility directs all output to your terminal. If you prefer, you can use the /LIST qualifier to generate a file containing the following information for each file on the disk:
To generate a disk usage accounting file, use the /USAGE qualifier. The first record of the file, called the identification record, contains a summary of disk and volume characteristics. The identification record is followed by a series of summary records; one summary record is created for each file on the disk. A summary record contains the owner, size, and name of the file.
When you enter the ANALYZE/DISK_STRUCTURE/SHADOW command, the system checks for shadow set discrepancies---to ensure that every block on the disk is identical. A discrepancy is a block that should be the same on all members but is not. For example, when you enter a WRITE command, it might not be written to all the members when the ANALYZE/DISK/SHADOW processes it.
If a discrepancy is found, a clusterwide WRITE lock is taken on the shadow set, and the questionable blocks are reread. Then either one of two actions occurs:
In addition, this utility might report explainable discrepancies between the shadow set members if either of the following occurs:
$1$DGA20: (18 GB)
$1$DGA21: (36 GB)
You can eliminate inconsistencies by performing a full merge. To
initiate a full merge, enter the DCL command SET SHADOW/DEMAND_MERGE
DSAxxx. If the devices are served by controllers that support
controller-based minimerge (for example, HSJ50s), enter this command
while the shadow set is mounted on only one node within the cluster.
Otherwise, a minimerge occurs, and the discrepancy might not be
resolved. When you add members to a single member shadow set, a full
copy operation also ensures that the disk is consistent both within and
outside the file system.
3.2 ANALYZE/DISK_STRUCTURE Usage Summary
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.
Usage Summary Use the following command to invoke the utility:
device-nameSpecifies 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, see the MOUNT documentation in this manual.
ANALYZE/DISK_STRUCTURE device-name: /qualifiers
To repair a disk effectively, you must have read, write, and delete access to all files on the disk. To effectively scan a disk (/NOREPAIR), you must have read access to all files on the disk. You must also have write access to INDEXF.SYS to force the flushing of the caches for this file. You must also have write access to BITMAP.SYS for the same reason: to force the flushing of the caches for this file. (You need write access to QUOTA.SYS only if the volume is running disk quotas.)
For a complete explanation of file access, see the HP OpenVMS Guide to System Security.
When you use the /REPAIR or /LOCK_VOLUME qualifier, only the process running the ANALYZE/DISK_STRUCTURE Utility has access to the file system. This means that active files such as SYSUAF, RIGHTSLIST, log files, and especially AUDIT_SERVER journal and log files that might exist on the target device are stalled while ANALYZE/DISK_STRUCTURE is running.
Stalling includes OPEN, CREATE, CLOSE, file EXTEND, and TRUNCATE operations. Stalling occurs on all nodes within the cluster that have the volume mounted.
If you specify /REPAIR, the utility uses the ACP control lock volume function to prevent creation, deletion, extension, and truncation activity while the volume is being rebuilt. In this way, the volume is prevented from being modified while the operation is in progress.
If you specify /NOREPAIR, the volume is not locked; the utility does
not attempt to write to the disk. However, if users perform file
operations while you run the utility, you might receive error messages
that incorrectly indicate file damage. To avoid this problem, HP
recommends that you run ANALYZE/DISK_STRUCTURE when the disk is in a
3.3 ANALYZE/DISK_STRUCTURE Qualifiers
|/CONFIRM||Determines whether ANALYZE/DISK_STRUCTURE prompts you to confirm each repair|
|/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 and I64) 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_ATTRIBUTES||Determines whether ANALYZE/DISK_STRUCTURE 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|
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.
You can use the /CONFIRM qualifier only with the /REPAIR qualifier. The default is /NOCONFIRM.
$ ANALYZE/DISK_STRUCTURE DBA0:/REPAIR/CONFIRM %VERIFY-I-BACKLINK, incorrect directory back link [SYS0]SYSMAINT.DIR;1 Repair this error? (Y or N): Y %VERIFY-I-BACKLINK, incorrect directory back link [SYSEXE]SYSBOOT.EXE;1 Repair this error? (Y or N): N
The command in this example causes the Analyze/Disk_Structure utility to prompt you for confirmation before performing the indicated repair operation.
Erases home blocks from a volume whose home blocks were not deleted during previous initialization operations.
You can use the /HOMEBLOCKS qualifier only with the /REPAIR qualifier. The operation can take 30 minutes to complete.
$ ANALYZE/DISK_STRUCTURE DBA0:/REPAIR/HOMEBLOCKS
The command in this example causes the Analyze/Disk_Structure utility to erase home blocks on DBA0.