A CFRM policy structure specification has too large a difference
between the INITSIZE and SIZE values.
Explanation
CHECK(IBMXCF,XCF_CF_STR_POLICYSIZE) found an exception.
A
specification of INITSIZE in the active or pending CFRM policy indicates
an initial structure size that is too small for the maximum structure
size (as determined by the SIZE specification). Either a structure
has an initial size specified as less than half the maximum size,
or a structure whose users do not allow structure alter has an initial
size specified different than the maximum size.
When allocating
the structure initially, whether INITSIZE is specified or not, the
system attempts to build all control structures that will be required
to support the maximum size of the structure. These control structures
are built in the control storage allocation of the structure. For
structures whose users do not allow structure alter, the control storage
allocated to accommodate larger sizes is wasted. An INITSIZE value
substantially smaller than the SIZE value might cause the following
conditions:
- It might be impossible to allocate a structure at a size of INITSIZE,
because the amount of control storage required to support the
SIZE value might actually be larger than INITSIZE.
- If the allocation succeeds, it might result in a structure with
a proportionally large amount of its storage allotted to structure
controls, leaving too few structure objects to be exploited usefully
by the associated application.
See accompanying message IXCH0923I for more information.
System action
The system continues processing.
Operator response
Report this problem to the system programmer.
System programmer response
IBM® suggests
that the INITSIZE and SIZE specification for structures be determined
by the CfSizer (Coupling Facility Structure Sizer) tool: http://www.ibm.com/systems/support/z/cfsizer
Use
the CfSizer tool to determine the INITSIZE and SIZE parameters for
structures with an exception condition. Update the CFRM policy (or
policies) with the new parameters. The new parameters should not have
an INITSIZE value for a structure less than half the SIZE value for
that structure. If alter is not allowed by users of a structure, INITSIZE
should not be specified for that structure. Start an updated policy
with the following system command:
SETXCF START,POLICY,TYPE=CFRM,POLNAME=polname
The
policy changes will become pending and affect only future structure
allocations, not currently allocated structures. REBUILD or REALLOCATE
can be used to activate the pending changes for currently allocated
structures. For example, a REALLOCATE process can be started with
the following system command:
SETXCF START,REALLOCATE
Problem determination
See IXCH0923I in the message buffer that
identifies the coupling facility structures with an exception condition.
The
problem may have occurred because a CFRM policy structure SIZE value
was adjusted without also adjusting the INITSIZE value (or vice versa).
The
following system command can be used to determine the name of the
active or pending CFRM policy:
DISPLAY XCF,POLICY,TYPE=CFRM
Source
Module
Routing code
Descriptor code
3 is the default set by this check. See note
1.
Reference Documentation
For more information
on planning and activating CFRM policies, see z/OS MVS Setting Up
a Sysplex.
For the syntax of the SETXCF START command, see "SETXCF
Start Command" in z/OS MVS System Commands.