Hitachi MK-96RD647-01 manual

Note: For 01-02-48 and earlier, do not access the FX volume from FAL/FCU when AIX is accessing it. For 01-02-50 and earlier, do not access the FX volume from FAL/FCU when Windows 2000/2003/Windows NT is accessing it.

Note: Please note the following restrictions for the listed operating systems:

•For UNIX operating systems, if the version is 01-02-48 and later, FXotm can run several different datasets simultaneously.

•For Windows 2000/2003/Windows NT operating systems, if the version is 01- 02-50 and later, FXotm can run several different datasets simultaneously.

•For AIX operating systems, since volumes are reserved during accessing, FXotm cannot run several different datasets simultaneously.

Please refer to the Reference Manual for RAID 200/300/400/450 FAL & FCU, revision 20.0, for more detail.

The FX volumes can only be accessed by open-system hosts using the FAL/FCU software. The z/OS hosts have normal read/write access to the -B and -A volumes, read-only access to the -C volumes, and no access at all to the OPEN-xFMT volumes. The open-system hosts have read/write access to the -C, -A, and OPEN-xFMT volumes and read-only access to the -B volumes. The open-system hosts must use FAL/FCU to access all FX volumes.

WARNING: Concurrent access to the FX volumes by the z/OS and open- system hosts is not supported. The user is responsible for managing access to FX volumes to avoid I/O contention between the z/OS and open-system hosts. Since FCU accesses only the VTOC area of the FX -B volumes, catalog or security control functions cannot be used to provide access control for the 3390-3B volumes.

The z/OS host can issue a reserve command to reserve a volume for exclusive use. The z/OS reserve command prevents access by all other hosts, including all other z/OS hosts and all open-system hosts. The open-system host can also reserve a volume to exclude I/Os issued by other systems. The open-system reserve command prevents access by all other open-system hosts, but z/OS hosts still have normal access to FXmto and FXotm volumes reserved by open-system hosts. These reserve commands affect FX operations as follows:

•Reserved by z/OS host. When an FX volume is reserved by the z/OS host, FX operations cannot be performed on that volume, because the FAL/FCU access from the open-system host will terminate unsuccessfully. Open- system access other than read or write I/Os can be executed successfully.

Note: Open-system access to an z/OS-reserved volume may complete successfully if the open-system retries the operation after the reserve is released. However, since the time interval before a retry varies depending on the open-system platform and the z/OS application that issued the reserve, the success of retry operations on reserved volumes cannot be guaranteed.

About Cross-OS File Exchange Operations 2-31

Hitachi USP V Cross-OS File Exchange User’s Guide