User's Guide
Table Of Contents
- SCSI Command Support
- SCSI Commands
- Initialize Element Status - 07h
- Initialize Element Status With Range - E7h
- Inquiry - 12h
- Log Sense - 4Dh
- Mode Select (6) - 15h
- Mode Select (10) - 55h
- Mode Sense (6) - 1Ah
- Mode Sense (10) - 5Ah
- Mode Pages
- Move Medium – A5h
- Persistent Reserve In – 5Eh
- Persistent Reserve Out – 5Fh
- Position to Element – 2Bh
- Prevent Allow Medium Removal – 1Eh
- Read Buffer – 3Ch
- Read Element Status – B8h
- Release Element (6) – 17h
- Release Element (10) – 57h
- Report LUNS – A0h
- Request Sense – 03h
- Request Volume Element Address - B5h
- Reserve Element (6) - 16h
- Reserve Element (10) - 56h
- Send Diagnostic - 1Dh
- Send Volume Tag - B6h
- Test Unit Ready (00h)
- Write Buffer (3Bh)
Quantum Scalar Intelligent Libraries SCSI Reference Guide Guide 9
Fibre Channel Interface Support
The library Fibre Channel ports can be N_Ports for point-to-point topologies or NL_Ports for arbitrated loop
topologies. Only Class 3 service is supported. Private arbitrated loops are supported if the library is not
attached to a Fibre Channel fabric, and public arbitrated loops are supported if the library is attached to a
Fibre Channel fabric.
Logical Libraries
The underlying physical library is not exposed externally to applications. Rather, logical representations of
media changer devices are created, and these are presented instead. Through this method the physical
library can be partitioned and concurrently shared in a heterogeneous environment. Storage and Data
Transfer elements cannot be shared across logical libraries; they can only be assigned to one logical library
at a time. The Medium Transport element (the robotic mechanism) is shared across all logical libraries, and
as a result there may be some delays encountered as each logical library waits its turn for this shared
resource.
Depending on library model, Import/Export elements can also be shared across logical libraries. This is
further discussed in Mailbox Behavior
. All other aspects of the logical media changer devices are identical
to an independent physical media changer device.
Mailbox Behavior
The following characteristics affect Import/Export elements:
• The Import/Export elements are contained in removable magazines. When the magazines are
removed, the elements are still counted in the number of Import/Export elements and will have
element descriptors returned for them in response to a READ ELEMENT STATUS command. Their
element status will indicate that they are not accessible, and will also report an exception with an
ASC/ASCQ of 3B/12.
• Some libraries are configured with multiple physical mailboxes, each containing their own set of
magazines. Whenever a mailbox is opened, the status for the elements it contains will indicate that
they are not accessible until the mailbox is closed again.
• The mailbox magazine(s) can be assigned to and shared by different logical libraries. The Import/
Export elements they contain are then used on a “first come, first served” basis. When shared
Import/Export elements are in use by one logical library, element status for those elements will
indicate that they are empty, but not accessible for all other logical libraries that share them. The
presence of media and associated volume tag information will only be available to the logical library
using the elements at that time. When media is removed from the shared elements, they become
available for use by the next logical library requesting them, and their element status indicates that
they are accessible.
IDENTIFY 80h-
FFh
Both These messages are sent either by the initiator or
by the target to establish (or re-establish) the
logical connection path (nexus) between an initiator
and target for a particular logical unit.
Table 6 Supported SCSI Messages (Continued)
Message Code Direction Description