The installation steps below must be followed to prevent job failures
from occurring.
- Ensure that all systems in the JES3plex are at z/OS V2R1 (this
is needed because pre-execution and job execution can occur on different
systems in the JES3plex). JES3 itself, however, can be at a lower
release level.
- Make JES3 INISH deck changes as described in INISH deck example.
The INISH deck changes define the library-specific distributed names
associated with the distributed libraries "clusters" in a TS7000
Virtualization Engine. All TS7700 Virtualization Engines being used
by JES3 (with devices connected to the host) should have the new esoteric
names defined, regardless of whether the TS7700 Virtualization Engine
is part of a single or a multi-cluster grid.
- Roll-out the JES3 INISH deck changes to all systems in the JES3plex
(this roll-out can occur one system at a time). The new esoteric
names will not be passed to JES3 until the support is enabled through
DEVSUPxx.
- By default, the device allocation assist function is enabled at
the library for all specific allocations. However, starting with Release
1.7 of the TS7700 Virtualization Engine, this support can be disabled
either by a tape hardware specialist (PFE) dialing into the library
or starting with Release 2.0 of the TS7700, through the MVS LIBRARY
REQUEST command. Verify that the DAA function is enabled at the
library by using the LIBRARY REQUEST,composite-library-name,SETTING
command.
- Lastly, enable the support to the host through the DEVSUPxx PARMLIB
member using the JES3_ALLOC_ASSIST=YES keyword (either at IPL or through
the SET DEVSUP=xx operator command). The SET DEVSUP=xx operator
command can be used to enable this support by routing the command
to all systems in the JES3plex. Once this support is enabled, the
new library-specific distributed names can be returned to JES3. Ensure
that steps 2 and 3 are completed before enabling this support; otherwise,
job failures can occur if JES3 does not understand the new esoteric
names being passed (because they were not defined in the JES3 INISH
deck).
If one of the systems in the JES3plex lags behind (in
enablement of this support), all that might occur is that the device
allocation assist preferred cluster list might not be honored. JES3
and MVS allocation will still see the same list of eligible devices.