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

Tape and DVD
4.6.4. DLT 7000 and DLT 8000 Tape Subsystems
Note: DLT 8000 tape subsystems are supported only in the 35-GB mode configured as
the DLT 7000. All information in this subsection applies to both DLT 7000 and DLT 8000
tape subsystems.
The DLT 7000 tape subsystem connects through SCSI-2W channels. The DLT 7000 tape
subsystem will not work on SCSI narrow channels.
DLT 7000 tape subsystems provide a maximum capacity per cartridge of 35 GB of
uncompressed data (up to 70 GB of compressed data) and a sustained data transfer rate
of 5 MB per second. Tape subsystems use the LZ1 data compression technique.
Tape cartridges use half-inch tape. These cartridges are not interchangeable with
cartridges used with 9-, 18-, and 36-track tape drives.
The Exec provides unique equipment mnemonics for configuring the subsystem and a
unique specific assign mnemonic for assigning tape files. Other than the generic assign
mnemonic T, existing assign mnemonics used to assign half-inch cartridge tapes cannot
be used to assign DLT 7000 tape drives.
The Exec supports DLT 7000 tape subsystems as boot devices and system dump
devices. They can also be used for checkpoint/restart. Checkpoint can assign DLT 7000
tape devices with the new assign mnemonic DLT70, or the more generic assign
mnemonic T. Restart can assign DLT 7000 tape devices with the new assign mnemonic,
DLT70.
Considerations for the DLT 7000 tape subsystem are as follows:
• Read backward I/O functions are not supported. If a read backward is attempted, it is
terminated with an I/O error status of 024 (octal).
• DLT 7000 tape drives are not compatible with any other OS 2200 tape device.
• The LED display is not supported by the Exec due to a DLT 7000 hardware limitation;
therefore, the Exec does not display either system-ID or reel-ID on the drive.
• The Exec does not support all densities or write capabilities that the DLT 7000
hardware supports. Table 4–2 lists the capabilities that are supported and those that
are not supported by the Exec.
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