Chapter 8: Disk Space Analysis › Disk Space Analysis Utility

Disk Space Analysis Utility

Use the ADVISE COLLECT REPORT DISK_SPACE command to obtain information about disk volumes. The following are prerequisites when using this utility:

• The volume must be in FILES-11 ODS-2 or ODS-5 format.
• The volume must be mounted without the /FOREIGN qualifier.
• You must have READ access to the files [0,0]BITMAP.SYS and [0,0]INDEXF.SYS on the volume to be analyzed. Generally, this is satisfied by the SYSPRV privilege.

The report command is of the following type:

$ ADVISE COLLECT REPORT DISK_SPACE/qualifier device-name,...

This command accepts one or more parameters and a qualifier (explained below). The parameters are the names of disk devices on which to report. Physical or logical device names may be specified.

The Performance Agent software contains a knowledge base including rules for evaluating disks. These rules may recommend generating this report for specific devices. You may also want to create this report for disks that are more than 70% full. Before giving the ADVISE COLLECT REPORT command, you can display a list of disk devices on your system using the DCL command SHOW DEVICES.

During the analysis, the volume is locked to prevent storage allocation. The files BITMAP.SYS and INDEXF.SYS are read and the volume is unlocked. The command does not write to the volume being analyzed unless the report file you specify resides on that volume.

By default, the disk information is written to the device defined by the logical SYS$OUTPUT. Using the /OUTPUT qualifier, you can specify the output report name.

The following command writes a disk volume report for disks COOLER and BURGUNDY to the file DISKSPACE.RPT in the current directory:

$ ADVISE COLLECT REPORT DISK_SPACE/OUTPUT=DISKSPACE.RPT-
_$ COOLER,BURGUNDY

The following command writes a disk volume information report for device HSC000$DUA0 to the file DUA0.RPT:

$ ADVISE COLLECT REPORT DISK_SPACE/OUTPUT=DUA0.RPT HSC000$DUA0

The Disk Space report contains four sections: Detailed Volume Analysis, Summary of Free Storage, Summary of Allocated Space, and Files with Extension Headers.