ClearPath OS 2200 Series Release 13.2 Software Planning and ...

OST4890
Tape and DVD
OST4890 is a 36-track tape subsystem that is attached to ClearPath systems through
SCSI-2W channels.
The OST4890 is a functionally compatible tape subsystem as compared to the existing
OST5136 tape subsystem; as such, the Exec provides a unique control unit mnemonic
for configuring this subsystem but no new assignment mnemonic and thus no new
device equipment mnemonic is created. The existing OST5136 device assignment
mnemonic, HIC51, is used for assigning tape files for the OST4890. The existing
OST5136 device equipment mnemonic, U5136, is also used for configuring the OST4890
devices.
Note: You need to install SCSITIS if your site is configured with an OST4890
subsystem.
Considerations for the OST4890 tape subsystem are as follows:
• Due to the new control unit equipment mnemonic introduced by this feature,
products that are sensitive to this mnemonic are affected.
• Currently, all existing OST5136 customers use freestanding drives. The OST4890
tape subsystem has been specifically designed by StorageTek to configure in a
single-size 9710 ACS library managed by ACSLS software. If your site has both
OST5136 freestanding drives and OST4890 ACS drives, the following potential
compatibility issues might exist when using the HIC51 mnemonic:
− Drive allocation will be based on the location of the volume. If the library has the
volume-id, an OST4890 drive will be selected. If the library does not have the
volume-id, a freestanding OST5136 drive will be selected.
− In case you want to force the assignment to an OST5136, you may use the pool
of NONCTL to force a drive allocation outside of the library.
You can always use absolute device assignments.
• If your site uses the 9710 library, and eventually migrates to a larger library (for
example, CLU6000), you will need to change all HIC51 assign mnemonics. If you are
planning to migrate to a larger library, use HICM for the OST4890 usage to avoid
potential mnemonic changes. However, if you use HICM for the OST4890 drives,
and then add a larger library (for example, CLU6000), you could have two competing
libraries. In this case, the query/polls would assign a drive in the correct library based
on the location of the volume-id. If you add the freestanding U47M instead, the drive
allocation will be purely based on whether the library software (that is, ACSLS)
returns a positive-poll for a specified volume-id. If the library has the volume-id, an
OST4890 drive will be selected. If the library does not have the volume-id, a
freestanding U47M drive will be selected.
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