HP XP20000XP24000 Disk Array - Manual (Page 22)

2-4 About Cross-OS File Exchange Operations
Hitachi USP V Cross-OS File Exchange User’s Guide
FX Volume Types
The FXmto and FXotm volumes are z/OS devices that can only be accessed by
open-system hosts using the FAL/FCU software. The FXoto volumes are open-
system devices that cannot be accessed by z/OS hosts. FX operations are
performed using the following types of FX volumes on the TagmaStore USP
and NSC subsystems:
• FXmto, FXotm. The FX -A volumes can be used for FXmto and FXotm
operations. z/OS hosts have normal read/write access to -A volumes. Open-
system hosts have read/write access to -A volumes but must use FAL/FCU to
access these volumes as raw devices (no mount operation). Figure 2-3 shows
the structure of the FX -A volumes.
Label area
Datasets
Management area
MAINFRAME OPEN SYSTEM
Read/Write Read/Write
Cyl#0
Cyl# max.
Cyl# 0
Cyl# MAX.
VTOC
Figure 2-3 3390-3A/9A/LA Volume Structure (FXmto, FXotm,
FXoto)
Note: The -A volumes are not write-protected. Do not execute any open-
system write operations to -A volumes (except disk partitioning and
labeling). Do not create a file system on an -A volume; this will overwrite
the data exchange files on the volume.
• FXmto. The FX -B volumes can only be used for FXmto operations. z/OS
hosts have normal read/write access to -B volumes. Open-system hosts have
read-only access to -B volumes and must use FAL/FCU to read these volumes
as raw devices (no mount operation). The -B volumes are write-protected
from open-system access. The TagmaStore subsystem will reject all open-
system write operations to -B volumes (except disk partitioning and labeling)
to protect the z/OS data on these volumes. Figure 2-4 shows the structure of
the FX -B volumes.