Technical data

2–50 Replacement Procedures
Replacing an EMU
Use the following steps in and to replace the EMU.
Removing an EMU
1. From a host console, stop all host activity and dismount the logical units in the
subsystem.
2. Connect a PC or terminal to the maintenance port of one of the controllers in
your subsystem.
3. Shut down the controllers. In single controller configurations, you only need to
shut down “this controller.” In dual-redundant controller configurations, shut
down the “other controller” first, then shut down “this controller” with the
following commands:
SHUTDOWN OTHER_CONTROLLER
SHUTDOWN THIS_CONTROLLER
When the controllers shut down, their reset buttons and their first three LEDs are
lit continuously. This may take several minutes, depending on the amount of data
that needs to be flushed from the cache modules.
4. Turn off all the ac input boxes for each expansion enclosure.
CAUTION: ESD can easily damage an EMU. Wear a snug-fitting,
grounded ESD wrist strap.
5. Disengage both retaining levers and remove the EMU.