NonStop S-Series Planning and Configuration Guide (G06.26+)

Planning for System Configuration
HP NonStop S-Series Planning and Configuration Guide—523303-017
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Kernel-Managed Swap Facility (KMSF)
Kernel-Managed Swap Facility (KMSF)
Kernel-managed swap space manages virtual memory using swap files controlled by
the operating system. Pages of memory not currently in use are swapped, or copied, to
disk during a shortage of available physical memory. These memory pages are
swapped back or overwritten to physical memory when the code or data are needed.
When swapped to disk, the data are stored in swap files. Through the Kernel-Managed
Swap Facility (KMSF), the operating system opens one or more swap files for each
processor and manages the files for all the processes needing them. Proper
configuration and management of kernel-managed swap space is critical to the
operation of your system.
When you set up a new system, you must configure KMSF swap files. Using the
guidelines provided in the Kernel-Managed Swap Facility (KMSF) Manual, you must
decide:
•
How much swap space to configure
•
Where to place swap files
•
What guidelines you need to create for operations staff to monitor and alter swap
files
Initial Configuration of KMSF Swap Files
New systems are initially configured with these default KMSF swap files:
Changing the Configuration of KMSF Swap Files
You must change the configuration of KMSF swap files if:
•
Your system is using the default swap file configurations. These configurations are
minimums for system load. To run most applications, you need to configure
additional swap files for your system.
•
You want to increase the number or size of your swap files.
•
You want to change the location of one or more swap files.
The Kernel-Managed Swap Facility (KMSF) Manual describes how to configure KMSF
swap files.
Attribute Value
Location $SYSTEM
Number 1 swap file for each processor
Name $SYSTEM.ZSYSSWAP.SWAPnn,
where nn is the processor number
Size 128 MB with at least 64 MB allocated