6.1 Firmware upgrades The firmware upgrade process of the IBM SAN32B-E4 switch or IBM SAN768/384 director is the same as on any other IBM SAN b-type Fibre Channel (FC) switch. However, because of the encryption capabilities of the IBM SAN32B-E4 and IBM SAN768/384, there are several peculiarities and items to which you need to pay attention. In this section, we assume that you are familiar with the regular firmware upgrade process, and we will not explain the basics of it. Use the IBM Support site documentation for reference for the regular firmware upgrade process. We only focus on the important points, which can be vital to the data and the I/O flow: The IBM SAN32B-E4 and IBM SAN768/384 with Encryption Blades firmware upgrade is an I/O disruptive upgrade, because the EEs and backplanes are reset after the firmware download/upgrade. We suggest that you perform the firmware upgrade in a high-availability (HA) cluster environment so that the encryption I/O traffic is not disrupted. With only one EE maintaining the encryption I/O, you will always have I/O interruption during a firmware upgrade. To avoid this situation, you must back up the existing EE with the other EE, forming an HA cluster. In an HA cluster, perform the firmware upgrade one node at a time, so the other node will take over the Crypto Target Containers (CTCs)/logical unit numbers (LUNs) and I/O during the firmware upgrade. In the data encryption key (DEK) cluster, manually move the CTC to another node in the cluster before upgrading the firmware, and then move it back. The following general guidelines are for a firmware upgrade of the IBM SAN32B-E4 and IBM SAN768/384 with Encryption Blades in encryption groups (EGs), HA clusters, and DEK