Julyl 2017 Operation and Configuration Details 21
3
Operation and Configuration Details
This chapter provides details for operation and configuration that are important
while writing host applications.
Multiple Initiator Support
The library architecture supports multiple initiators with the following details:
• Unit - Reserve and Release commands are supported. Persistent Reserve
commands are also supported. Host software applications should perform
reservations whenever possible.
• If an initiator modifies a mode page, all other initiators will then receive a unit
attention indicating the mode parameters have changed.
• The library maintains separate prevent or allow medium removal status for each
initiator. If any host/initiator has issued a prevent command, then the mailslot
cannot be opened and the magazine(s) cannot be unlatched.
Host Timeout Characteristics
Host timeout values for SCSI commands may require adjustment based on the
configuration of the library.
Device Reservations
The SL150 tape library support both the Reserve/Release management method and
also the Persistent Reservations management method.
• TABLE 3-1 outlines the reservation restrictions placed on commands for the
Reserve/Release method, defined in the ANSI SCSI-3 Primary Commands (SPC-
2) standard.
• TABLE 3-2 defines the reservation restrictions placed on commands for the
Persistent Reservations method, defined in the ANSI SCSI-3 Primary Commands
(SPC-3) Standard.
Conflict Command will not be performed and the library will terminate the
command with Reservation Conflict status.
Allowed Command will be allowed to execute to normal completion.