About Cross-OS File Exchange Operations 2-31
Hitachi USP V Cross-OS File Exchange User’s Guide
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-x FMT volumes. The open-system hosts have read/write access to
the -C, -A, and OPEN-x FMT 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.
