Kernel-Managed Swap Facility (KMSF) Manual

Kernel-Managed Swap Facility (KMSF) Manual—425824-005
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Managing KMS Files
You manage KMS space using NSKCOM, a utility program for the operating system.
Using NSKCOM, you can perform the following functions:
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Create a configured swap file
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Display static and dynamic information about both default and configured swap
files
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Put a swap file into use
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Alter the maximum extents and threshold of a swap file
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Stop the future use of a swap file
•
Delete a swap file from the KMS configuration
•
Purge a swap file from disk
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Get help on NSKCOM commands
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Log your NSKCOM session to a log file
•
Establish default values for subsequent NSKCOM commands
•
Find the version of NSKCOM that is running
You must be a super-group user (255, n) in order to change the KMSF configuration by
adding or deleting swap space. For detailed information on these functions, see
Section 4, NSKCOM Command Reference.
This section describes how to monitor your KMS files and how to manage and change
your KMSF configuration.
Monitoring KMS Space
Periodically monitor your KMS files to ensure that you have adequate swap space
available. If inadequate swap space is available, it might prevent process creation and
cause processes that try to increase their available memory (through the
RESIZESEGMENT procedure call) to fail.
Guidelines for Monitoring KMS Space
How often you choose to monitor your KMS file configuration depends on your
particular system configuration and usage. A general guideline is to closely monitor
your swap files for at least one month after installing a new release to ensure that you
understand your peak usage and that your swap configuration meets your needs. After
the first month, monitor KMS files as appropriate for your system usage. The more
dynamic the system workload, the more often you should monitor KMS files.
Once you have some experience with kernel-managed swapping on your system, you
might be able to rely on monitoring the Event Management Service (EMS) logs for
swap messages. KMSF generates EMS messages to notify you of changes in the
swap file environment, such as swap files whose usage has been disabled or enabled,
swap files that have exceeded their usage threshold, and so on. KMSF messages