Environmental; Backup Power Management; Table 2-5 Response To Various Ac Power Conditions - Compaq StorageWorks RAID Array 3000 Controller Shelf User Manual

Environmental

The controller incorporates a set of on board sensors to detect abnormal
operating conditions that may affect data safety.

Backup Power Management

The controller must be connected to the UPS to prevent the subsystem cache
from being corrupted during unexpected losses of power. If no backup power
supply is provided, the controller will remain off-line and reject all I/O
requests with a status of Check Condition/Hardware Error.
During normal operation, the controller AC power is supplied from a line
source through both power cords to both power supplies. Conditions of poor or
no power cause the following UPS responses:
Condition
Low line voltage
No line voltage
(AC loss)
UPS low-battery
warning
UPS power down
Table 2-5
Response to Various AC Power Conditions
Response
UPS compensation circuit automatically increases output
voltage, without placing load on the UPS battery.
UPS switches to the battery, which supplies power to the
controller maintaining full functionality.
UPS signals controller of impending power down. Caching is
disabled but the controller continues to service host requests
and begins to flush cache to disk.
UPS signals controller of impending power down. Subsystem
discontinues host services. Cache flush is completed.
UPS shuts itself off, preventing complete battery discharge. All
data has been written to disk.
RAID Array 3000 Controller 2-19