The library supports unit reserve, release, and persistent reserve commands. An initiator may reserve elements that will then cause a reservation conflict if the reserved element is accessed by a different initiator. Host software should reserve resources 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 a separate "prevent" or "allow" media removal state for each initiator. If any host/initiator has issued a prevent command, then no access to the Cartridge Access Port (CAP) door will be allowed. See "Prevent/Allow Medium Removal (1Eh)".
If any initiator sends an Allow Media Command (Prevent bit set to 0), the library clears the prevent bit for all hosts and allows the operator to open the CAP.
Host timeout values for SCSI commands may require adjustment based on the configuration of the library.
The library architecture provides for optional fast load operations. The following applies only if the fast load option is disabled:
The robot will mount a tape to a drive and wait at the drive location until the tape is fully loaded before beginning another task.
A SCSI move command may require additional time to complete. The host software must adjust SCSI time-out values to allow for the tape drive load time in addition to the robotics motion time.
The library supports the following reservation management methods:
Reserve and Release — defined by the ANSI SCSI-3 Primary Commands (SPC-2) Standard. See Table 2-1 for command reservation restrictions.
Persistent Reservation — defined by the ANSI SCSI-3 Primary Commands (SPC-3) Standard. See Table 2-2 for command reservation restrictions.
Table 2-1 and Table 2-2 use the following definitions:
Conflict — The library terminates the command with a Reservation Conflict (18h) status.
Allowed — The library executes the command normally.
The library returns 0 for the Compatible Reservation Handling (CRH) bit in the Persistent Reserve In (5Eh) Report Capabilities Data page.
A CRH value of 0 indicates the library processed the reserve or release command as defined in SPC-2. Therefore, the library will return a Reservation Conflict (18h) when it receives a reserve or release command from the same initiator that holds the persistent reservation.
Table 2-1 Reserve and Release Management Method Command Restrictions
| Command | Action when the Library is Reserved by Another Initiator |
|---|---|
|
Initialize Element Status (07h) |
Conflict |
|
Initialize Element Status w/Range (37h) |
Conflict |
|
Inquiry (12h) |
Allowed |
|
Log Sense (4Dh) |
Allowed |
|
Mode Select (15h/55h) |
Conflict |
|
Mode Sense (1Ah/5Ah) |
Conflict |
|
Move Medium (A5h) |
Conflict |
|
Persistent Reserve In (5Eh) |
Conflict |
|
Persistent Reserve Out (5Fh) |
Conflict |
|
Position to Element (2Bh) |
Conflict |
|
Prevent/Allow Media Removal (1Eh) |
Prevent = 0, Allowed Prevent = 1, Conflict |
|
Read Element Status (B8h) |
Conflict |
|
Release (17h) |
AllowedFoot 1 |
|
Report LUNs (A0h) |
Allowed |
|
Report Target Port Groups (A3h) |
Allowed |
|
Request Sense (03h) |
Allowed |
|
Request Volume Element Address (B5h) |
Conflict |
|
Reserve (16h) |
Conflict |
|
Send Diagnostics (1Dh) |
Conflict |
|
Send Volume Tag (B6h) |
Conflict |
|
Test Unit Ready (00h) |
Conflict |
Footnote 1 The reservation is not released.
Table 2-2 Persistent Reservation Command Restrictions when the Library is Reserved by Another Initiator
| Command | Non-Registered InitiatorFoot 1 | Registered Initiator: Exclusive Access ReservationFoot 2 | Registered Initiator: Exclusive Access Registrant Only Foot 3 |
|---|---|---|---|
|
Initialize Element Status (07h) |
Conflict |
Conflict |
Allowed |
|
Initialize Element Status w/Range (37h) |
Conflict |
Conflict |
Allowed |
|
Inquiry (12h) |
Allowed |
Allowed |
Allowed |
|
Log Sense (4Dh) |
Allowed |
Allowed |
Allowed |
|
Mode Select (15h/55h) |
Conflict |
Conflict |
Allowed |
|
Mode Sense (1Ah/5Ah) |
Conflict |
Conflict |
Allowed |
|
Move Medium (A5h) |
Conflict |
Conflict |
Allowed |
|
Persistent Reserve In (5Eh) |
Allowed |
Allowed |
Allowed |
|
Persistent Reserve Out (5Fh) - SA=Register |
Allowed |
Allowed |
Allowed |
|
Persistent Reserve Out (5Fh) - SA=Reserve |
Conflict |
Conflict |
Conflict |
|
Persistent Reserve Out (5Fh) - SA=Release |
Conflict |
AllowedFoot 4 |
AllowedFootref 4 |
|
Persistent Reserve Out (5Fh) - SA=Clear |
Conflict |
Allowed |
Allowed |
|
Persistent Reserve Out (5Fh) - SA=Preempt |
Conflict |
Allowed |
Allowed |
|
Persistent Reserve Out (5Fh) - SA=Preempt/Abort |
Conflict |
Allowed |
Allowed |
|
Persistent Reserve Out (5Fh) - SA=Register and Ignore |
Allowed |
Allowed |
Allowed |
|
Position to Element (2Bh) |
Conflict |
Conflict |
Allowed |
|
Prevent/Allow Media Removal (1Eh) Prevent = 0 |
Allowed |
Allowed |
Allowed |
|
Prevent/Allow Media Removal (1Eh) Prevent = 1 |
Conflict |
Conflict |
Allowed |
|
Read Element Status (B8h) |
Conflict |
Conflict |
Allowed |
|
Release (17h) |
Conflict |
Conflict |
Conflict |
|
Report LUNs (A0h) |
Allowed |
Allowed |
Allowed |
|
Report Target Port Groups (A3h) |
Allowed |
Allowed |
Allowed |
|
Request Sense (03h) |
Allowed |
Allowed |
Allowed |
|
Request Volume Element Address (B5h) |
Conflict |
Conflict |
Allowed |
|
Reserve (16h) |
Conflict |
Conflict |
Conflict |
|
Send Diagnostics (1Dh) |
Conflict |
Conflict |
Allowed |
|
Send Volume Tag (B6h) |
Conflict |
Conflict |
Allowed |
|
Test Unit Ready (00h) |
Conflict |
Conflict |
Allowed |
Footnote 1 Action when a non-registered initiator sends a command to a library reserved by another initiator.
Footnote 2 Action when a registered initiator sends a command to a library reserved by another initiator that has an Exclusive Access reservation.
Footnote 3 Action when a registered initiator sends a command to a library reserved by another initiator that has an Exclusive Access Registrant Only reservation.
Footnote 4 The reservation is not released.
When there is a multi-port Fibre Channel card installed in the library, the additional Fibre Channel ports must be activated using a Hardware Activation file in order for all ports to be fully operational.
Note:
Port 1 is always activated.The library can receive commands on an unavailable port. However, the library only fully supports the following commands on an unavailable port:
For all other commands, the library:
Terminates the command with Check Condition (02h) status
Sets the sense key to Not Ready (02h), ASC to 04h, and ASCQ to 0ch — Not Ready, Logical Unit Not Accessible, Target Port in Unavailable State
Use SLC to configure partitioning and SCSI host access to each partition (see the SL3000 Library Guide). To grant access, you must provide the Host World Wide Port Name and a LUN. All hosts must have a connection to LUN 0. Additional LUN configuration will allow access to more than one partition.
Example 2-1 SCSI Host Access in a Library with Two Partitions
Partition 1 could have the following host access:
Partition 2 could have the following host access:
When Host 2 sends a command on LUN 0, the library directs the commands to partition 1. When Host 2 send a command on LUN 1, the library directs the command to partition 2.
If a SCSI host sends a command to a partition it does not have access to, the library will respond with the following:
Inquiry returns Good (00h) with the Inquiry Data Peripheral Qualifer set to 001b instead of 000b.
Request Sense returns Good (00h) with the sense data set to LUN Access Not Authorized (02h/74h/71h).
Report LUNs returns Good (00h) and the Report LUNs Data reports LUN 0.
All other commands return Check Condition (02h) with the sense data set to LUN Access Not Authorized (02h/74h/71h).
For more information on sense data, see "Additional Sense Codes and Qualifiers".
CAPs may be shared between partitions with the same interface type. However, Oracle recommends that you do not use shared CAPs for SCSI partitions. You should dedicate a CAP that each SCSI partition. Access to shared CAPs must be carefully managed and you must assign the CAP to a partition using SLC before you can insert or eject a cartridge.
See the SL3000 Library Guide "Operating CAPs" chapter for detailed information.
See the SL3000 Library Guide "Library Addressing" appendix for more details on the SCSI element addressing scheme. The SCSI element address depends on the element type. Each library or partition uses a fixed starting address for each element type. Then, within each element type, the element addresses are sequential.
| Element Type | Starting SCSI Element Address |
|---|---|
| Medium Transport Element (Robot) | 0 |
| Import/Export Elements (CAPs and AEMs) | 10 |
| Data Transfer Elements (Drives) | 1000 |
| Storage Elements (Cartridge Cells) | 2000 |