Although there is no benefit to configuring an OAMplex when using
a file system, OAM does provide some limited support for using a file
system within an OAMplex.
When a file system is to be used by OAM in an OAMplex, all systems
in the OAMplex must meet the following requirements (in addition to
those identified in
OAMplex):
- For any storage group that will include the file system sublevel,
the object storage group definitions in the SCDS must be set to ENABLE
for all systems in the OAMplex.
- The SETDISK statements in the CBROAMxx member
of PARMLIB must be identical for all systems in the OAMplex . To meet
this requirement, it is recommended that the ONLYIF statement be used
so that a single CBROAMxx member can be
used by all systems in the OAMplex.
- The file systems identified in the SETDISK statements must be
available to all systems in the OAMplex because OAM file system operations
could be performed from any system in the OAMplex. To do this, these
file systems must be defined through z/OS UNIX as a shared file
system. In a shared file system environment, a file system mounted
by one system participating in a shared file system is accessible
to all systems participating in the shared file system. Establishing
a shared file system is described in z/OS UNIX System Services Planning.
OAM cannot detect or prohibit configurations that do not meet
the requirements. An improper configuration can lead to unpredictable
results.
OAMplex and Recall to Disk: There are cases when an OAMplex
configuration will result in read requests being shipped from one
system in the OAMplex to another system in the OAMplex. When the read
request is the result of an application OSREQ RETRIEVE request, then
it is possible that the object will need to be recalled to the disk
level of the OAM storage hierarchy. Whether the object is recalled
to the DB2 sublevel or file system sublevel of the disk level of the
OAM storage hierarchy depends on the capabilities of both the originating
system and the target system involved in the request and on the configuration
of the target system:
- If both systems are z/OS V1R13 or above, the recall disk sublevel
(DB2 or file system) will be determined by the configuration in place
on the target system, not the originating system, consistent with
the existing protocol for other OAMplex related processing.
- If both systems are not at z/OS V1R13 or above, the target
system will recall the object to the DB2 sublevel.
OAMplex and file system deletion processing: In an OAMplex,
it should be assumed that file system physical deletions could be
performed by any system in the OAMplex. Physical file system deletions
will be accomplished by processing the entries in the File System
Delete Table. OAM determines which system will perform the physical
file system deletions and the actual timing of the physical file system
deletions.