Lenovo DM120S Service Manual page 45

...
The next step depends on the storage disk show -port command output:
Step 7.
If the output shows...
All disk drives in the stack are connected
through path A and path B except for the ones
in the disk shelves you disconnected, which
are only connected through path B
Anything other than the above
Step 8. Complete the following substeps for the disk shelves (in the stack) you are removing:
a. Repeat Step 5 through Step 7 for path B.
Note: When you repeat Step 7 and if you have recabled the stack correctly you should see all
disk drives connected through path A and path B.
b. Repeat Step 1 to confirm that your system configuration is the same as before you removed
one or more disk shelves from a stack.
c. Go to the next step.
Step 9. If when you removed ownership from the disk drives (as part of the preparation for this procedure),
you disabled disk ownership automatic assignment, reenable it by entering the following command;
otherwise, go to the next step: storage disk option modify -autoassign on
For HA pair configurations, you run the command from the clustershell of both controllers.
Step 10. Power off the disk shelves you disconnected and unplug the power cords from the disk shelves.
Step 11. Remove the disk shelves from the rack or cabinet.
To make disk shelves lighter and easier to maneuver, remove the power supplies and IOM12
modules. Avoid removing the disk drives if possible, because excessive handling can lead to
internal damage.
CAUTION:
It is recommended that you use a mechanical hoist or lift if you are moving a fully populated
DS460C disk shelf, which can weigh 249 lb (113 kg).
Then...
Go to the next step.
You successfully bypassed the disk shelves
you are removing and reestablished path A on
the remaining disk drives in the stack.
Repeat Step 5 and Step 6.
You must correct the cabling.
.
Chapter 7 Hot-removing disk shelves with IOM12 modules
41