v Logical Library 4: Slot 34 through slot 45 4096 (x1000) through 4107 (0x100B)
SCSI Element Addressing
Every logical library starts at the first drive slot with the current assigned element
start address (default value 256). It will be incremented from the bottom to the top
slots for every drive slot. There is one exception to this addressing scheme to
accommodate libraries currently in the field. A 4U library which contains only full
height drives will continue to have the addresses assignments 256 and 257, thus
causing no interruptions to their operation. Drive slots will still be incremented by
1 for each drive slot position.
Note: Exchanging drives with different form factors will result in the library
needing to be reconfigured.
The SCSI specification does not allow gaps in the SCSI element addressing. Special
handling is needed for empty drive slots to fulfill the specification. Also
temporarily removed drives need to have their addresses preserved to not confuse
the attached host and host application. Generally only drives which are currently
physically available or temporarily removed are reported. Empty (unused) slots
located at the bottom or the top should not be reported, with an exception in case
of a “removed” condition. A drive slot which does not contain a drive, and has a
position between used slots, needs to be reported as a SCSI element. To signal the
host application that this slot is not usable, its ACCESS bit will be disabled.
a77ug1
64
Drive 3
256
Element Address
Drive 2
256
Element Address
Drive 1
256
Element Address
Magazine
1
Magazine
2
Magazine
3
Magazine
4
Front side
Drive 4
256
Element Address
Figure A-4. Configuration of a four - partition system
SCSI Element Slot
4
3
2
1
SCSI Element Slot
4
3
2
1
257
256
257
256
258
4U Unit with only FH drives
(1 logical library)
4U Unit with FH and HH drives
(1 logical library)
a77ug1
65
Figure A-5. Examples of SCSI element addressing
A-6 Dell PowerVault TL2000 Tape Library and TL4000 Tape Library User's Guide
To Next Page
Loading...
