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EMC Fibre Channel Disk-Array Processor Enclosure (DPE) Hardware Reference
Installing a Rackmount DPE
DPE Powerup and Initialization
The only power switches on a DPE are those on the power supply,
which are normally covered by the drive fan pack. As a result, a DPE
is always active.
When ac power is initially applied to a DPE, the disk drives power up
and spin up in a specified sequence. The maximum delay is 48
seconds for the last drive to start spinning in a DPE, and 84 seconds
for the last drive to start spinning in a DAE. The same delays occur
when you insert a drive while a DPE is powered up.
DPE Powerdown
If DPE (with an SPS option) is powered down abnormally (e.g., a
brown out or ac failure), data is saved to the storage-system vault
disks, and not lost. However, when the DPE is powered back up
again, it may take longer to come online.
Turning Off the Power 1. Stop all I/O activity to the DPE.
Stopping the I/O allows the SP to destage cache data, and may take some
time. The length of time will be based on criteria such as the amount of cache,
the amount of data in the cache, the type of data in the cache, and the target
location on the disks.
2. If the server connected to the DPE is running the UNIX®
operating system, unmount the file systems.
3. Shut off power to the ac distribution strips that supply the DPE.
The power in the distribution strips may be controlled by a circuit
breaker located inside the cabinet (if the cabinet has such
breakers) or externally to the cabinet.