DGADSIOX I/O exit limitations and security considerations
Checkpoint/restart is not supported when using DGADSIOX I/O exit for the following reasons:
- I/O exits in general including do not support Checkpoint/restart
- The IBM® ADRDSSU utility does not support Checkpoint/restart
- Control cards are allow for wild-carded input
In addition, the ADRDSSU utility does not support DUMP/RESTORE of z/OS UNIX System Services user files such as PATH='/u/kstic1/abc.txt'. However, ADRDSSU does support HFS files.
The DGADSIOX I/O Exit utility program invokes DFSMSdss to perform requested functions by calling the ADRDSSU utility via the cross-memory application interface, documented in DFSMSdss Storage Administration. This cross-memory interface causes a DFSMSdss server address space to start under the ASPACE name of DGADSIOX.
For HFS and ZFS type files, there are restrictions related to UNIX System Services that may result in failures or hangs without proper security. Please refer to DFSMSdss Storage Administration (Application programming interface, Cross-memory application interface restrictions) for a description of the restrictions and set up requirements related to HFS and ZFS files.
When using DUMP/RESTORE to copy a ZFS File System, a separate IDCAMS VERIFY must be done following the COPY. This can be done with the DGADTSUB Run Task utility or with IDCAMS outside of IBM Connect:Direct. Without the VERIFY, any access to the restored ZFS File System will receive an OPEN error (RC=116 orx’74’) and the data will not appear usable. VERIFY must be performed prior to mounting the ZFS File System. This requirement does not apply to HFS File Systems nor to individual ZFS files copied using DGADSIOX