The contents of the GRSCNFxx parmlib member are used
during system initialization to define the attributes of global resource
serialization processing.
A global resource serialization complex consists of two
or more systems connected by communication links. The systems in the
complex use global resource serialization to serialize any shared
resources such as controlling access to data sets on shared DASD volumes
at the data set level rather than at the volume level. (For more information,
see z/OS MVS Planning: Global Resource Serialization.)
The majority of GRSCNFxx parameters are specific to
defining a global resource serialization ring complex. However, GRSQ
is specific to star mode, and the following keywords are relevant
for all modes, including GRS=NONE:
- SYNCHRES
- ENQMAXA
- ENQMAXU
- AUTHQLVL
- MONITOR
To define a global resource serialization ring complex, use the
GRSCNFxx parmlib member. GRSCNFxx contains a GRSDEF statement for
each system. The statement identifies:
- The name of the system in the complex, by means of the MATCHSYS
parameter.
- The CTC links assigned to the system, by means of the CTC parameter.
- The minimum amount of time that the RSA-message is to spend in
the system, by means of the RESMIL parameter.
- Whether or not the system identified by the MATCHSYS keyword has
the automatic restart capability, by means of the RESTART parameter.
- Whether or not the system identified by the MATCHSYS keyword has
the capability to automatically rejoin the complex, by means of the
REJOIN parameter.
- The maximum amount of time (the tolerance time interval) before
global resource serialization will detect a timeout, by means of the
TOLINT parameter.
- The method to establish the global resource serialization ring
acceleration function, by means of the ACCELSYS parameter.
- The member of parmlib that contains the default global resource
serialization component tracing options, by means of the CTRACE parameter.
There are three basic ways to use GRSCNFxx to define your complex:
- You can create one GRSCNFxx parmlib member that contains GRSDEF
statements that define all of the systems in the complex. After creating
the member, copy it to the parmlib on each system. As each system
is initialized, it reads the GRSCNFxx member, locates its own GRSDEF
statement, and uses the information in the statement during initialization.
- You can create a unique GRSCNFxx member for each system in the
complex. The member consists of a GRSDEF statement for that particular
system. You place the unique member in parmlib on that particular
system, and that system uses the information it contains during initialization.
- If all systems in the global resource serialization complex will
belong to the same sysplex, you can create one GRSCNFxx member that
contains a single GRSDEF statement that defines consistent information
for all systems. The IBM-supplied default member, GRSCNF00, can be
used for this purpose.
Variations or combinations of these methods are, of course, possible.
Which ever method you choose, GRSCNFxx provides information about
the configuration of the complex that global resource serialization
requires during initialization. Other information that global resource
serialization requires comes from the following system parameters
(in IEASYSxx):
- GRS=
- GRSCNF=
- GRSRNL=
- SYSNAME=
The GRS, GRSCNF, GRSRNL, and SYSNAME parameters can
only be specified at IPL time, either in IEASYSxx or by the operator.
They all remain in effect for the duration of the IPL. For specific
details about how to specify any one of these parameters, see the
description of the parameter provided in IEASYSxx (system parameter list).
During initialization processing for a system that is to join an
existing complex, global resource serialization verifies that the
information in GRSCNFxx is consistent with the existing complex. Even
if a system is defined in a GRSCNFxx parmlib member and initialized
with GRS=JOIN, it cannot join the complex unless either: