This parameter specifies the number of entries in
the address space vector table (ASVT) that are to be reserved for
address spaces created in response to a START command (such as an
initiator, the APPC address space or the library lookaside address
space). The RSVSTRT entries are only used after the number of entries
specified by MAXUSER is obtained. It is not recommended to depend
on using the RSVSTRT entries under normal operating conditions. By
reserving RSVSTRT entries in the ASVT for such address spaces, you
can often avoid having to reinitialize the system because there is
no available entry in the ASVT for a critical address space. For example,
if library lookaside (LLA) ends and you issue a START LLA command
to restart LLA, but no ASVT entry is available, LLA does not be restarted.
However, if there are reserved entries for critical address spaces
(such as LLA), it is more probable that an entry will be available
and the LLA address space can be created without having to reinitialize
the system. However, too large a buffer can cause
the system to allocate more system resources than are needed during
a given IPL. The excessive allocation of system resources because
of incorporating too large a buffer can lead to potential problems
such as the following examples:
- The specification of RSVSTRT in conjunction with CSCBLOC=BELOW
and MAXUSER can cause the system to allocate excessive storage below
16M. See CSCBLOC for
details.
- An aggressively large MAXUSER, RSVSTRT, and RSVNONR can cause
the system to allocate an excessive amount of storage, which can potentially
lead to a wait state 204 reason 008 at IPL time. (Wait state 204 with
reason 008: An error occurred during allocation initialization; the
system could not obtain storage for device information.)
If started tasks or batch jobs that create non-reusable
ASIDs end enough times, they will exhaust all available ASIDs and
an IPL will be required. When loading the initial program is not an
acceptable option, determine which programs caused the problems and
fix them. For methods that prevent running out of ASIDs, see .
Value
Range: 0-32767. Note that the sum of the values specified for
the RSVSTRT, RSVNONR, and MAXUSER system parameters cannot exceed
32767.
Default Value: 5
Associated Parmlib
Member: None