- IBM switch Users and Maintenance Guide

power to the storage server. Go to “Turning on the storage server” on page 66
and follow the procedure described there before proceeding with the following
step.
9. Make sure that the green Power LED on the new power-supply CRU is on and
the amber Fault LED is off.
v If the Power LED is off, the power-supply CRU might not be installed
correctly. Remove it and then reinstall it.
v If the Fault LED is on or the Power LED stays off, test the power source to
verify that the outlet is working properly.
For more information about the LEDs, see “Checking the LEDs” on page 71.
Working with RAID controllers
The DS4100 base storage server operates with two RAID controllers that can be
hot-swapped.
The DS4100 single-controller storage server has only one RAID controller. If you
are replacing a failed RAID controller in the DS4100 single-controller storage server,
you do not need to power down the DS4100 before replacing the RAID controller.
If you are replacing a functioning (non-failed) RAID controller in the DS4100
single-controller storage server, do not remove or replace the RAID controller in the
DS4100 single-controller storage server without first stopping the host applications,
unmounting the logical drives from the host server, and powering down the storage
subsystem.
Attention: Before you replace a RAID controller, verify that the replacement RAID
controller part number match the part number of the RAID controller be replaced.
Each RAID controller fits into the back of the storage server and has the following
components:
v Battery
v Cache memory
v Two host ports and one expansion port
Note:
The expansion port is inactive in the DS4100 single-controller storage
server.
v One Ethernet port
v One serial port
Each
RAID controller has a unique hardware Ethernet address, which is printed on
a label on the front. There is also a label giving the cache battery manufacturing
and installation dates on the top of the controller unit. Figure 70 on page 95 shows
the location of these items.
Important: Please read the following information before replacing a RAID controller.
v The cache battery is not included with the controller CRU.
v To provide full functionality in a DS4100 base storage server, the two controllers
must have the same memory capacity. To ensure that you replace the failed
controller with an appropriate replacement controller, verify that the FRU number
of the replacement controller matches the FRU number of the failed controller.
There are no protection mechanisms to block out an incorrect CRU from being
94 IBM TotalStorage DS4100 Storage Server: Installation, User’s, and Maintenance Guide