Online Configuration Tasks
HP NonStop S-Series Hardware Installation and FastPath Guide—541880-001
12-8
KMSF
KMSF
Kernel-managed swap space manages virtual memory using swap files controlled by
the operating system. During a shortage of available physical memory, pages of
memory not currently in use are swapped, or copied, to disk. These memory pages are
swapped back or overwritten to physical memory when the code or data is needed.
When swapped to disk, the data is 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
system operation.
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 decide:
•
How much swap space you should configure
•
Where to place swap files
•
What guidelines to create for operations staff on monitoring and altering 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
Change the configuration of KMSF swap files if:
•
Your system is using default swap file configurations. These configurations are
minimums for system load. To run most applications, you must configure additional
swap files.
•
You want to increase the number or size of your swap files.
•
You want to change the location of one or more swap files.
KMSF and the Operations Environment
KMSF affects routine operations. Operations staff must monitor KMSF and operator
messages to spot potential problems and dynamically add swap space as needed.
Event Management Service (EMS) messages are generated to alert staff to swap files
that have reached a configured threshold and to changes in KMSF configuration.
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
