Powerup And Initialization - Dell DAE2-ATA Hardware Reference Manual

Installing a DAE2

Powerup and Initialization

2-12 2-Gigabit Disk-Array Enclosure (DAE2) Hardware Reference
Do not power up a disk enclosure without at least one LCC installed.
You can configure a driveless disk enclosure within a Fibre Channel loop.
High availability with write-caching requires disks in slots 0-4 in the first
DPE2 or DAE2 connected to a storage processor (Enclosure Address 0,
loop 0).
7. Set any SPS switches, and then the main circuit breaker switches,
to the on position. The disk enclosures in the cabinet power up.
The only power switches that control most DAE2s are those on the
SPS and the cabinet circuit breakers, which are normally on. If a DAE2
power/cooling module includes a power switch, it is usually on as
well. As a result, a DAE2 is always active.
When you initially apply ac power to a disk enclosure, the disk drive
modules power up according to their specifications, and spin up in a
specified sequence dictated by enclosure and loop IDs. The slot
spin-up delays range from 0 to 84 seconds. The same delays are used
when you insert a drive module while the system is powered up.
The LCC hardware monitor (FRU monitor) resets and begins its
control loop. The port bypass circuits enter the states indicated by
their associated drives. The monitor continues to run in this local
mode until it receives commands that dictate otherwise. In local
mode, the monitor maintains the port bypass circuits in the same
states as the drive command signals. When a drive fault occurs, the
corresponding drive fault light turns on. Firmware commands can
take control of the port bypass circuits and the drive status lights.
CAUTION
!
Each drive reads its FC-AL physical address only at powerup or
when the drive is reset. To avoid potential data loss, you must set
the enclosure address when you install the disk enclosure and
power is off; you cannot change the EA while power is on.