Configuration File Reference › EXTENT Record › Description

Description

The disk space in an extent is allocated through the subpools specified on an EXTENT record. (For more information about subpools, see SUBPOOL Record in the chapter "Configuration File Reference.")

CA VM:Secure assumes that an extent resides on the DASD identified by the VOLUME record that immediately precedes an EXTENT record. This means that, in the DASD CONFIG file, each EXTENT record must appear immediately after its corresponding VOLUME record.

Note: For more information about volumes, see VOLUME Record.

Additionally, SUBPOOL records must appear before they are referenced by an EXTENT record. You cannot continue an EXTENT record beyond one line.

Multiple extents can be defined for a single volume, but they cannot overlap. Minidisk definitions cannot cross over extent boundaries.

Minidisks defined outside extents are not controlled by CA VM:Secure; overlapping minidisk definitions are not detected for these minidisks. All disk space used for CMS minidisks should be identified by EXTENT records.

Note: Minidisk extents can start in cylinder 0 on CKD DASD or in blocks 0 through 15 on FBA DASD. Use caution when using these cylinders or blocks because these areas are used by CP to hold the device’s label and, on CP OWNED volumes, the allocation information. If the CMS FORMAT command is used against a minidisk that starts in these areas, it will re‑label the entire device. The ability to define minidisks as cylinder or block 0 is intended for situations in which the device is dedicated to a second‑level guest as a full pack minidisk.

Note: Additionally, minidisk extents should not cover alternate areas on a DASD. See the appropriate IBM planning and administration documentation for the location and size of alternate areas for each DASD.

Example

The following EXTENT records, immediately preceded by their VOLUME record, define volume VMPK11:

VOLUME VMPK11 3380
EXTENT  0       001   * CP ALLOC MAP AREA
EXTENT  2       401   SYSTEMS DEV1 TEST1
EXTENT  402     552   * CP PAGING AREA #1
EXTENT  553     884   MAIN SYS1 TEMP