Technical data

Chapter 2: Upgrading Trays in the Storage Array 11
 Each controller canister in the E5400 controller-drive tray has two sockets for
cache memory DIMMs and a cache backup memory device. Use this procedure
to upgrade existing cache memory DIMMs and, if necessary, add a cache backup
memory device.
 Each controller canister in the E2600 controller-drive tray has one socket for
cache memory DIMMs and a cache backup memory device. Use this procedure
to upgrade existing cache memory DIMM and, if necessary, add a cache backup
memory device.
Upgrading Cache
Memory for the
CE7900 Controller
Tray
Before you start this procedure, gather antistatic protection, cache memory DIMMs,
and, if necessary, cache backup memory devices. Perform each of the following tasks
in order.
1. Remove the controller canisters from the controller-drive tray or a controller tray.
2. Upgrade the cache memory DIMM.
3. Upgrade the Cache Backup Memory Device.
4. Reinstall the controller canisters from the controller-drive tray or the controller
tray.
ATTENTION Data loss or corruption might result if the steps in this upgrade
procedure are not followed correctly – You must upgrade the cache memory DIMMs
and the cache backup memory devices in both controller canisters in the controller tray
or the controller-drive tray. Otherwise, you receive event messages indicating that the
controllers have mismatched and incompatible configurations. This event might cause
the controllers to lock down.
NOTE Do not perform this upgrade procedure with the power turned on. This
procedure requires that you first set controller A offline to make sure that all of the
data, which is currently in cache on both controller canisters, is successfully written to
disk before the upgrade. Second, you will turn off the power to both controller canisters
as described in the steps for "Removing a Controller Canister" on page 11.
Removing a Controller
Canister
NOTE Before you remove the controller canisters, make sure that you set controller
A to Offline, as described in the following steps, to ensure that all the data currently in
the cache for controller A is successfully written to disk prior to the upgrade. This step
also ensures that the data currently in the cache for controller B is successfully written
to disk before you turn off the power to both controller canisters.
ATTENTION Possible hardware damage – To prevent electrostatic discharge
damage to the tray, use proper antistatic protection when handling tray components.