IBM DS4700 manual Controllers, Connectors, switch, and enclosure ID

subsystems such as DS4100 or DS4300 storage subsystems. The DS4700 Express E-DDM option CRUs are not interchangeable with those of the DS4200 Express and EXP420. When replacing an E-DDM CRU, be sure to order and install the correct E-DDM CRU. Using non-supported E-DDM options or FRUs will result in the E-DDM being locked out by the DS4700 Express controller firmware and might also damage the drive connector in the enclosure midplane.

Attention:

1.After you remove a E-DDM CRU, wait 70 seconds before replacing or reseating the E-DDM CRU to allow it to properly spin down. Failure to do so may cause undesired events.

2.Never hot-swap a E-DDM CRU when its associated green Activity LED is flashing. Hot-swap a E-DDM CRU only when its associated amber Fault LED lights is not flashing or when the E-DDM is inactive and its associated green Activity LED lights is not flashing.

Note: If the E-DDM you want to remove is not in a failed or bypass state, always use the Storage Manager client program either to place it in a failed state or to place the array that is associated with the E-DDM (or E-DDMs) in an offline state before you remove it from the enclosure.

Controllers

The DS4700 Express has two hot-swappable and redundant RAID controllers. The controllers are located at the back of the storage subsystem. The left controller is labeled controller A, and the right controller is labeled controller B. One controller will continue to operate if the other controller fails.

The controllers contain the storage subsystem control logic, interface ports, and LEDs. The controller on model 70 has two fibre channel host ports and the controller on model 72 has four fibre channel host ports that you could use to connect the storage subsystem to the host server. In addition, each controller for both DS4700 Express subsystem models 70 and 72 has two fibre channel drive ports for connecting to the DS4000 storage expansion enclosures and two Ethernet ports for DS4700 Express subsystem management purposes. See Figure 2 on page 10.

Although both controllers (A and B) are identical, they are seated in the DS4700 Express chassis in opposite orientations. See Figure 2 on page 10. If the controller cannot fully be inserted in the controller bay, flip it 180 degrees and reinsert it. Do not force fit because it may cause damage to the controller unit.

Connectors, switch, and enclosure ID

The controllers support fiber optic interfaces for both the host channel and drive channel ports. The controllers also contain two Ethernet ports for storage subsystem management purposes and a serial port that IBM Support uses to perform problem recovery and troubleshooting procedures.

The default IP addresses for the Ethernet ports on controller A are 192.168.128.101 and 192.168.129.101. The default IP addresses for the Ethernet ports on controller B are 192.168.128.102 and 192.168.129.102. The subnet mask for all cases are 255.255.255.0. See “Setting up IP addresses for DS4000 storage controllers” on page 11 for more information.

The enclosure ID, comprised of two seven-segment numbers, is located on the back of each controller next to the controller indicator lights. The two digits that

8IBM System Storage DS4700 Express Storage Subsystem: Installation, User’s and Maintenance Guide