The cluster data set must be allocated if a cluster session
is to be used in an LPAR.
Rules: You must follow these conditions in
order to create the necessary access:
- Catalog the cluster data set and make it accessible to the host
system (LPAR) that is to have a cluster session, as well as to the
system that processes the XRECOVER command for each of the SDMs that
will be coupled throughthe cluster session. The cluster
data set name is mhlq.XCOPY.ClusterName.CLUSTER.
The mhlq is the same high level qualifier
as used for the master data set. The ClusterName is
the value specified on XRC PARMLIB parameter of ClusterName of the
STARTUP category, or is defaulted to the host system name.
- Ensure that the cluster data set can reside on the same volume
as the master data set.
- Allocate the cluster data set without defining secondary extents.
- Allocate the cluster data set as physical sequential and not striped.
- Allocate the cluster data set with contiguous tracks as the I/O
is assumed not to span multiple extents. Access to the cluster data
set is controlled using GRS enqueues, and therefore, all systems with
coupled SDMs must be in the same GRS configuration.
- Allocate the cluster data set on a single disk device.
- Ensure that the required size of the cluster data set is one cylinder.
The required size of the cluster data set is fixed.
- Preallocate the cluster data set before specifying master session
name on the ClusterMSession PARMLIB parameter. Only the space that
is allocated at the time the ANTCLnnn address
space is started will be available for XRC use.
- Protect the cluster data set from unauthorized use.
- Do not allocate the cluster data set in the Extended
Address Space (EAS) of an Extended Address Volume (EAV).
Allocate the cluster data set with one cylinder primary
space and zero cylinders secondary space as follows:
DCB=(RECFM=FB,LRECL=15360,BLKSIZE=15360,DSORG=PS),SPACE=(CYL,(1,0))