Paging space requirements
DB2 requires paging, also called swap to be enabled. This configuration is required
to support various functions in DB2 which monitor or depend on knowledge of
swap/paging space utilization. The actual amount of swap/paging space required
varies across systems and is not solely based on memory utilization by application
software. It is only strictly required by DB2 on the Solaris and HP platforms due to
their use of early paging space allocation.
A reasonable minimum swap/paging space configuration for most systems is
25-50% of RAM. Solaris and HP systems with many small databases or multiple
databases tuned by STMM might require a paging space configuration of 1 x RAM
or higher. These higher requirements are due to virtual memory pre-allocated per
database / instance, and retained virtual memory in the case of STMM tuning