Lenovo DM120S Service Manual page 43

Step 4. If you are removing an entire stack of disk shelves, complete the following substeps; otherwise, go
to the next step:
a. Remove all SAS cables on Path A for the enclosure that you are removing. Then reattach the
SAS cables back to the upstream enclosure and ensure that you have connectivity back to all
enclosures on Path A. Remove the cables for path B on the enclosure you are removing. Then
ensure that you have reconnected the cables of all additional enclosures back on path B to
maintain your redundancy. This includes controller-to-shelf cables and shelf-to-shelf cables for
all disk shelves in the stack you are removing.
b. Go to step Step 9 on page 41.
Step 5. If you are removing one or more disk shelves from a stack (but keeping the stack), recable the path
A (IOM A) stack connections to bypass the disk shelves you are removing by completing the
applicable set of substeps:If you are removing more than one disk shelf in the stack, complete the
applicable set of substeps one disk shelf at a time.
Note: Wait at least 10 seconds before connecting the port. The SAS cable connectors are keyed;
when oriented correctly into a SAS port, the connector clicks into place and the disk shelf SAS port
LNK LED illuminates green. For disk shelves, you insert a SAS cable connector with the pull tab
oriented down (on the underside of the connector).
If you are removing...
A disk shelf from either end (logical first or last
disk shelf) of a stack
A disk shelf from the middle of the stack
A disk shelf in the middle of a stack is only
connected to other disk shelves—not to any
controllers.
Example
You can refer to the following cabling examples when removing a disk shelf from an end of a stack
or the middle of a stack. Note the following about the cabling examples:
Then...
1. Remove any shelf-to-shelf cabling from
IOM A ports on the disk shelf you are
removing and put them aside.
2. Unplug any controller-to-stack cabling
connected to IOM A ports on the disk shelf
you are removing and plug them into the
same IOM A ports on the next disk shelf in
the stack.The "next" disk shelf can be
above or below the disk shelf you are
removing depending on which end of the
stack you are removing the disk shelf from.
1. Remove any shelf-to-shelf cabling from
IOM A ports 1 and 2 or from ports 3 and 4
on the disk shelf you are removing and
IOM A of the next disk shelf, and then put
them aside.
2. Unplug the remaining shelf-to-shelf
cabling connected to IOM A ports on the
disk shelf you are removing and plug them
into the same IOM A ports on the next disk
shelf in the stack.
The "next" disk shelf can be above or below
the disk shelf you are removing depending on
which IOM A ports (1 and 2 or 3 and 4) you
removed the cabling from.
.
Chapter 7 Hot-removing disk shelves with IOM12 modules
39