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

Tape and DVD
• Audit trails cannot be configured to use DLT 7000 tape subsystems. You must be
aware of tape drive allocation while using the general assign mnemonic T in case it is
configured through SERVO TYPE SGS or as a standard system tape device. In this
case, the assigned DLT 7000 tape drive will be freed (@FREE) by the system and, if
there are other tape drives available, you are given an option to choose another type.
If the only tape drives available are DLT 7000 tape drives, you may have to
reconfigure the system for mass storage audit trail devices.
• The operator clean message to the system console is not supported for the DLT
7000 because the drive does not report ANSI standard requests for cleaning.
However, the DLT 7000 has an LED indicator that is lit when the drive needs
cleaning or the tape is bad. When DLT 7000 tape subsystems are part of a tape
library, the Automated Cartridge System Library Software (ACSLS) should be set to
the autocleaning-enabled mode. This enables the ACSLS and the library to perform
the cleaning.
• The SCSITIS separately packaged Exec feature must be installed in order to
configure DLT 7000 tape drives.
• Business Information Server (previously MAPPER) level 41R1 (or higher) and
TeamQuest LA level 6R3 (or higher) are required to support the DLT 7000 tape
subsystem.
• MMGR level 46R2 (HMP IX 5.0) or higher is required to support DLT 7000 tape
subsystems.
• Sort/Merge consideration—A tape volume for DLT 7000 tape subsystems can store
up to 70 GB of compressed data. In the past, unless a NUMREC parameter was
specified or scratch file were explicitly assigned, the SORT processor assumed that
tape files would fill tape volumes associated with the file. Based on that assumption,
the SORT processor would assign appropriately sized scratch files.
Because of the size of tape volumes for DLT7CT tape subsystems, the SORT
processor no longer makes that assumption. Now, the SORT processor assumes
that the last tape volume associated with each input file assigned to a DLT7CT tape
device contains 2 GB. If the last tape volume of a file contains more than 2 GB, you
must assign appropriately sized scratch files before calling the SORT processor or
passing a NUMREC or RECORD parameter to the SORT processor runstream.
• FAS consideration—DLT 7000 tape subsystems are not included in the Locate Block
Performance and FAS Usage Scenarios discussions under Performance
Considerations in the FAS Operations Guide because DLT 7000 tape subsystems do
not experience the same performance problems. However, tests indicate that
performance of this tape subsystem does not improve significantly until you access
files larger than 500,000 tracks.
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