Reservation Handling
The library supports two types of reservation management methods: Reserve and Release, and Persistent Reservation.
- Reserve and Release — defined by the ANSI SCSI-3 Primary Commands (SPC-2) Standard. See Reserve and Release Management Method Command Restrictions for command reservation restrictions.
- Persistent Reservation — defined by the ANSI SCSI-3 Primary Commands (SPC-3) Standard. See Persistent Reservation Management Method Command Restrictions for command reservation restrictions.
Compatible Reservation Handling Bit
A Compatible Reservation Handling (CRH) value of 0 indicates the library processed the reserve or release command as defined in SPC-2.
The library returns 0 for the CRH bit in the Persistent Reserve In (5Eh) Report Capabilities Data page. 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.
Reserve and Release Management Method Command Restrictions
For the reserve and release management method, the library imposes command restrictions when the library is reserved by another initiator.
- Conflict — The library terminates the command with a Reservation Conflict (18h) status.
- Allowed — The library executes the command normally.
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.
Persistent Reservation Management Method Command Restrictions
For the persistent reservation management method, the library imposes command restrictions when the library is reserved by another initiator.
- Conflict — The library terminates the command with a Reservation Conflict (18h) status.
- Allowed — The library executes the command normally.
Table 2-2 Persistent Reservation Command Restrictions when the Library is Reserved by Another Initiator
| Command | Non-Registered Initiator(2) | Registered Initiator: Exclusive Access Reservation(3) | Registered Initiator: Exclusive Access Registrant Only (4) |
|---|---|---|---|
|
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 5 |
AllowedFoot 6 |
|
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 2 Action when a non-registered initiator sends a command to a library reserved by another initiator.
Footnote 3 Action when a registered initiator sends a command to a library reserved by another initiator that has an Exclusive Access reservation.
Footnote 4 Action when a registered initiator sends a command to a library reserved by another initiator that has an Exclusive Access Registrant Only reservation.
Footnote 5
The reservation is not released.
Footnote 6
The reservation is not released.