With VDM, the Open VMS disk manager, you can free space on your disks by catching users who are gobbling up your free blocks. And, you can improve system performance, pinpoint problem files, tighten file security, detect low free space, and plan for the future. With VDM, you can fix disk problems before they get serious.
1. Identify specific or problem files
VDM's selection criteria allows you to identify files based on many criteria. In some cases you can also find these files with the DCL directory command, but VDM can accomplish the task in up to 1/10 the time. For instance you can find:
files that are marked NOBACKUP (or any other flag)
inactive or expired files
files based on size (used, allocated or difference between the two)
zero length files
files with fragmentation
files with a specified protection or ACE
files over/under/equal to a specified size
2. Use our preformatted reports to find various potential problems
Find users that are taking large amounts of disk space with the current usage report. This report can be generated for individual disks or the total of a number of disks.
Find users that are approaching their disk quotas.
Find out which disks may soon be full with the capacity planning reports.
Find all the UIC's on disks which own files but no longer have an UAF account responsible for them.
Find files consuming disk space because they need to be purged with the files report.
3. Pinpoint security problems
You can locate files with unusual access, such as WORLD:WRITE. VDM also allows you to list files with a specified ACE in the file's ACL.
4. Monitor and react to disk space problems
You can use VDM to check for and report low disk space. For each disk you can specify different thresholds and the action to be taken at each one. You can send messages to the console, mail yourself a message or even submit a batch job to clean up some disk space.
5. Plan for the future
You can project your future requirements using the rates of increase recorded in VDM's files. Use these reports to justify additional hardware.
6. Analyze Disk Usage
You can generate dozens of precise, informative reports based on selection criteria which you specify. These reports can be sorted by username, UIC, account, owner, or directory.
Some New Features in Version 6 and Version 7
VDM now includes a new, interactive, large files report. By default it will list the 50 largest files on the disk specified, in descending order of size. The new /NUM_FILES qualifier can be used to control how many files VDM includes in the report. The files can be selected by most blocks used, allocated or unused.
VDM now includes file type events with the monitor. VDM can check for and take action if a file becomes absent (gets deleted), present (gets created), grows or shrinks beyond a specified size, or has been changed since the last VDM data collection. VDM can send mail, operator messages and/or submit a batch job when a file event detects the appropriate condition.
The total number of events (disk or file) has been increased from 256 to 512.
The VDM files report could only be created during the batch data collections. VDM now includes a command procedure VDM_COM:FILE_REPORT.COM that can be used to create this report at anytime.
The VDM Monitor working set sizes have been increased for the detached process.
A new /ORGANIZATION qualifier allows you to select files by organization time when generating VDM interactive reports. Valid organizations are SEQUENTIAL, INDEXED and RELATIVE.
If the logical name VDM$SHOW_COMMAND is defined to be anything but itself VDM will include the DCL command used to generate an interactive report at the bottom of the report for reference.
The VDM/MONITOR/STATUS command now displays file event status information as well as the disk monitor status.
A new user detail report has been added. This report has a separate page for each user showing their storage usage for every disk they have files on and the total space used.
A new file selection criteria has been added so that interactive reports, such as the size report, can be generated for specific files, file types or directories. Any portions of the file specification not given will be completed from the default specification of [*...]*.*;*
A new unauthorized files report shows all the files on a disk that belong to a UIC that is not currently in the UAF file. With this report you can quickly find files that should be deleted or reset to belong to a valid user.
VDM currently uses the system service $getdvi to obtain information on disk devices. When obtaining the name for the disk the item “DEVNAM” is used. In sites with HSC devices this DEVNAME changes when the HSC node is changed so that VDM current and capacity reports can no longer access historical information for that disk. A new logical name “VDM$USE_DISK_NAME” has been added; if it is defined, in the system table, to be FULLDEVNAM:
$ define /system VDM$USE_DISK_NAME FULLDEVNAM
that item will be used instead. This generates more consistent results at sites using HSC devices. For a typical nonHSC disk in a cluster the two device items would return devices names of:
Switching from the current method to the new “FULLDEVNAM” item, at sites that are currently running VDM, will leave historical information unavailable because of the disk name change. A command procedure, VDM_COM:CONVERT_OLD_DATA has been added to read an existing data file and convert all the disk references from the DEVNAM format to the FULLDEVNAM format. As long as a disk has not been moved since the older data was created this will successfully make older data available. The procedure requires the date from the data file name as a parameter; to convert data from October 13, 1999, for example:
$ @VDM_COM:CONVERT_OLD_DATA 19991013
The current and capacity directory reports can now be generated to any level, how-ever, during reporting any directory string that is too long is truncated.