Kernel-Managed Swap Facility (KMSF) Manual

Managing KMS Files
Kernel-Managed Swap Facility (KMSF) Manual—425824-005
3-12
Altering Swap Files
Altering Swap Files
Use the ALTER command to alter the maximum extents or threshold of a file. You can
increase the maximum extents of a file, or if the file is not fully reserved, decrease its
maximum extents. In Example 3-9, the maximum number of extents of a swap file is
increased to 512.
Stopping Swap Files
You can use the NSKCOM STOP command to disable a swap file for use by additional
processes. Current processes using the file are not affected. You might want to disable
future use of a swap file in the following situations:
•
To force swapping to one or more other swap files for the processor. Generally, the
KMSF attempts to distribute swapping needs across the available swap files for a
processor. By stopping a swap file, you force the load onto the other swap files.
•
To prepare for deleting a swap file that is currently in use.
Usage of the swap file may continue depending on whether the file is currently in use.
When you enter the STOP command:
•
If the file is not in use, the command completes immediately and you receive a
“STOP successful” message (Example 3-10).
•
If the file is in use, the file is marked for STOP in the ZSYSCFG file. NSKCOM
shows any STOP mark for a file in its informational commands, including STATUS,
INFO, and ENV. You receive a “STOP pending” message (Example 3-11).
Example 3-9. Altering a Swap File By Increasing MAXEXTENTS
NSK-ALTER SWAPFILE $SWAP.KERSWAP.CPU00A MAXEXTENTS 512
ALTER was successful: $SWAP.KERSWAP.CPU00A
NSK-
Note. If the target swap file is the only swap file open, NSKCOM responds with the error
“Cannot stop a CPU’s last open swapfile!” and does not stop the file.
Example 3-10. STOP Successful Message
NSK-STOP SWAPFILE $SWAP.KERSWAP.CPU00B
File $SWAP.KERSWAP.CPU00B Stop Pending altered in ZSYSCFG
STOP was successful: $SWAP.KERSWAP.CPU00B
NSK-