Reservation Conflict; Multiple Initiator Support; Host Timeout Characteristics; Fast Load - Sun Microsystems storagetek sl500 Reference Manual

Reservation Conflict

The library returns Reservation Conflict status (18) whenever a SCSI initiator
attempts to access a logical unit or element that is reserved by another initiator.

Multiple Initiator Support

The library architecture supports multiple initiators with the following details:
Up to 16 SCSI devices are supported. The library can be on a bus with a
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maximum of two initiators. In this configuration, the tape drive SCSI interfaces
would be required to be on a separate SCSI bus.
Unit - Reserve and Release commands are supported. Persistent Reserve
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commands also are supported. An initiator may reserve elements that will then
cause a reservation conflict if the reserved element is accessed by a different
initiator. Host software applications should perform reservations whenever
possible.
If an initiator modifies a mode page, all other initiators will then receive a unit
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attention indicating the mode parameters have changed.
The library maintains separate prevent/allow medium removal status for each
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initiator. If any host/initiator has issued a prevent command, then no access to
the Cartridge Access Port (CAP) door will be allowed.

Host TimeOut Characteristics

Host timeout values for the SCSI bus may require adjustment based on the
configuration of the library. The maximum timeout value is 10 minutes (for the
maximum library configuration.)

Fast Load

The library architecture provides for optional fast load operations. The following
applies only if the fast load option is disabled. (If the fast load option is disabled,
then the library's robot will mount a tape to a drive and wait at the drive location
until the tape is fully loaded before beginning another task.)
If the fast load option is disabled, a SCSI move command may require additional
time to complete. The library remains disconnected during this time. The host
software must adjust SCSI time-out values to allow for the tape drive load time in
addition to the robotics motion time.
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Multiple Initiator Support
Chapter 3 SCSI Bus Operations 29