Virtual Memory Kernel Tunables

Several virtual memory (VM) kernel tunables were changed to make system management easier.

Summary of Change

What’s New for Customers Migrating from HP-UX 11i v1 September 2005?

The following kernel tunables were removed:

eqmemsize
pfdat_hash_locks
region_hash_locks
swapmem_on
unlockable_mem




	TIP: To find information about other obsoleted kernel tunables listed in this document, perform a search on the word “tunable”.

The following kernel tunable was added:

eqmem_limit (only on PA-RISC systems)

What’s New for Customers Migrating from HP-UX 11i v2 June 2006?

See “What’s New for Customers Migrating from HP-UX 11i v1 September 2005?”

Impact

System administrators upgrading to HP-UX 11i v3 may want to remove the use of obsoleted tunables. A warning message will occur when attempting to set an obsolete tunable. With no changes, the system will still work correctly. In general, the goal is to make tuning one’s kernel easier.

Compatibility

The tunables pfdat_hash_locks and region_hash_locks have been obsoleted. The number of locks used will be automatically determined by the system.

The tunable swapmem_on has been obsoleted. Pseudo-swap will always be enabled, as was the default for previous releases of HP-UX.

The tunable eqmemsize has been replaced with the new tunable eqmem_limit. This is not a direct replacement. Most customers won’t want to set eqmem_limit, whether or not they previously set eqmemsize.

Performance

The tunable changes should not degrade performance.

In some configurations, setting eqmem_limit to a non-default value may improve performance; see the eqmem_limit manpage.

Documentation

For further information, see the following manpages:

Obsolescence

Not applicable.