HP 418800-B21 - StorageWorks Modular Smart Array 70 Storage Enclosure User Manual page 25

To protect the system from power-failure-related downtime, each disk enclosure ships standard with
a redundant power supply. Depending how you connect the power supplies to the power source,
you can eliminate downtime caused by power-related failures.
Connection Method
Disk enclosure power supplies
connected to:
one power source
Disk enclosure power supplies
connected to:
two separate power sources
Disk enclosure power supplies
connected to:
two UPS
two separate power sources
Level of Protection
Protects you from downtime when one of the disk enclosure power
supplies fails.
The remaining power supply/fan module can operate the disk
enclosure until you install a replacement module.
Protects you from downtime when one of the disk enclosure power
supplies fails.
Protects you from data loss when one of your power sources fails,
due to a pulled cable or tripped breaker.
The remaining power source can power the disk enclosure until the
failed power source is restored or relocated. Depending on the cause
and duration of the power outage, you can use this time to properly
shut down your storage sub-system.
Protects you from downtime when one of the disk enclosure power
supplies fails.
Protects you from data loss when one or both of your power sources
fails, due to a pulled cable, tripped breaker, or local power outage.
The remaining power source or the UPS will power the disk enclosure
until power is restored to the source. Depending on the cause and
duration of the power outage, you can use this time to properly shut
down your storage sub-system.
70 Modular Smart Array User Guide 25