Dell PowerVault ML6000 - Manual (Page 39)

Chapter 3 Description
Understanding Logical Element Addressing
Dell PowerVault ML6000 User’s Guide 39
Host software may have problems recognizing tape drives when tape
drives, 5U Library Control Modules, or 9U Library Expansion Modules
are added, removed, or replaced; or when partitions are added, deleted,
or modified, because existing logical element addresses can change.
Therefore, after making any of these types of modifications, you must
refresh the configuration of any backup application that manages the
library to reflect new tape drive positions. In addition, you may need to
reboot the host server(s) or rescan the bus to detect the changes.
See
Figure 12 on page 41 for a simple example of element addressing in a
14U library with a single partition, six tape drives installed and no empty
tape drive slots. Note that multiple partition can create complexity. If you
need help with the element addressing in your library, contact Dell
Technical Support (see Appendix C, Contacting Dell ).
Cartridge Slot Logical
Element Addressing
3
Tape cartridge slots
are assigned logical element addresses by partition.
The numbering is sequential within a partition and starts over with each
partition. Numbering begins at the top left slot (as you look at the library
from the front) in the lowest module in the library and moves
sequentially down the left-most column. The top left slot of every
partition is always number 4096, the slot beneath that is 4097, and so on.
When the numbering reaches the bottom of the column, it continues to
the top slot in the next column to the right (as long as it is in the same
module and partition) and moves down that column. When all of the
slots in the lowest module belonging to a partition have been accounted
for, numbering continues to the top left slot in the next module above (as
long as it is in the same partition). The numbering can get tricky when
partitions span modules and do not use all of the slots in a module.
Tape cartridge slots are assigned a logical element address whether they
contain a cartridge or not. Cartridges themselves are not given a logical
element address; only the slot is. Slot element addresses change when
slots are added or removed; partitions are added, removed, or modified;
or cleaning slots are added or removed.
I/E station slots
are numbered differently from partitions. Numbering
begins at the top I/E station slot in the uppermost module that contains
I/E station slots, and continues sequentially downward. This top slot has
element address 16. The slot beneath that is 17, and so on.
Cleaning slots
belong to the System partition and are not reported to the
host. Cleaning slots are skipped (they are not given a logical element
address), so adding or removing a cleaning slot will renumber all of the
slots in a partition.