NEC S2900 User Manual page 84

c) When you power on the disk array unit for the first time, you need to provide an initial setup for
the disk array unit by using the maintenance PC.
For a detailed setup procedure, see Appendix C "Use of Maintenance PC".
(2) Notes on turning off the AC power
The disk array unit periodically writes data in the cache memory onto a disk drive. If you turn off the
AC power before completion of a write to the disk drive, the remaining data in the cache memory is
backed up by the battery backup units.
However, the backup time is limited. (The backup time depends on the installed cache memory
capacity and the battery service period. See Section 2.2 "Write Cache Feature" for details.). To
securely protect your data, write all the data remaining in cache memory in the disk array unit onto the
disk drive according to the following procedure. Then turn off the AC power according to the
procedure explained in "(3) Turning off the AC power".
1. Turn off the power of the host system and the host bus adapter or the FC-AL switch.
Alternatively, offline all the paths connected to the host system that is connected with the disk
array unit.
2. Push the SHUTDOWN switch located on the front of the array controller by using the stick
attached to the key for at least 5 seconds.
When the POWER LED starts flashing, release the stick from the switch.
3. Confirm that the [POWER LED] on the front panel of the array controller goes off, and then
turn off the AC power according to the procedure explained in "(3) Turning off the AC
power".
If [POWER LED] lights or flashes, the data in the cache memory is being written onto the
disk drive. Do not turn off the AC power.
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