Battery Backup Unit
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Battery Backup Unit
When the optional battery backup unit fails, the following events occur:
•
The battery backup unit’s service light turns on.
•
If the storage system is using the cache, the storage system’s
performance may become sluggish while it writes any modified pages
from the cache to disk.
•
Caching is disabled; the cache state as shown in the raid5 getcache
command is “Disabled.” Caching is not re-enabled until the battery
backup unit is replaced with a fully charged one.
The raid5 getcrus output has three possible states for the battery backup unit:
Faulted (removed), Charging, and Present (fully charged or charging). If the
battery backup unit takes longer than an hour to charge, it shuts itself off and
transitions to the “Faulted” state.
If the fault light comes on or if the battery backup unit state is shown as
“Faulted” in the raid5 getcrus command output, have the battery backup unit
replaced as soon as possible by a Silicon Graphics System Service Engineer.
Storage-Control Processor
This section discusses
•
diagnosing SP failure
•
using the auto-reassign capability
Diagnosing SP Failure
When an SP fails, the storage system’s performance may become sluggish if
the storage system is using caching. You may find that one or more physical
disk units are inaccessible. The failed SP’s service light turns on, and the
service light on the front of the storage system turns on.
