- IBM switch Users and Maintenance Guide

Figure 5 shows the components at the back of the DS4100 single-controller storage
server. The DS4100 single-controller storage server has a controller blank instead
of a second RAID controller and a power supply blank instead of a second power
supply.
RAID controller
Each RAID controller contains three ports for Small Form-Factor Pluggable
(SFP) modules that connect to the fibre channel cables. Two of the SFP
ports (labelled Host 1 and Host 2) are for host server attachment. The third
SFP port (labelled Expansion) is used to connect additional expansion units
to the storage server.
Note: In the DS4100 single-controller storage server, the third SFP port
(labelled Expansion) is present but not active.
Each RAID controller also contains a battery to maintain cache data in the
event of a power failure. For more information, see “Cache memory and
RAID controller battery” on page 75.
Attention: You will lose access to data if you attempt to hot-swap the RAID
controller in a DS4100 single-controller storage server.
Hot-swap fans
The storage server has two interchangeable hot-swap and redundant fan
CRUs. Each fan CRU contains two fans. If one fan CRU fails, the second
Hot-swap fan bays
Hot-swap
power supplies
Raid controllers
f10ug021
Figure 4. Back view of DS4100 base storage server
Hot-swap fan bays
Power supply
RAID controller
f10ug021b
Figure 5. Back view of DS4100 single-controller storage server
10 IBM TotalStorage DS4100 Storage Server: Installation, User’s, and Maintenance Guide