Table of Contents
Advertisement
|
|
|
|
|
|
RAID controller cache battery
operation (thus eliminating the need to access the drive itself), and a write operation
is completed when data is written to the cache, rather than to the drives.
Note: On the FAStT600 single-controller storage server (Model 6LU/6LX), the RAID
controller's cache memory is used for storing read data only. The controller
firmware ignores a "write-cache enabled" setting. This protects data in the
event of a controller failure, which would cause the cache to be inaccessible.
See the storage-management software documentation for information on setting
cache memory options.
The RAID controller has a Cache active LED that displays the current status of the
cache. The LED is on if there is data in the cache, and it is off if there is no data in
the cache.
If caching is enabled and the Cache active LED never comes on during I/O activity,
it indicates that the cache memory has failed or the battery has failed (the green
Battery LED will be off).
Note: Always use the storage-management software to check your cache memory
settings before assuming a hardware failure.
Figure 46 shows the location of the Cache active LED on the front of the RAID
controller.
Figure 46. Cache active LED
Each RAID controller contains a sealed, rechargeable 4-volt lead-acid battery. This
battery provides cache backup for up to three days in the event of a power loss.
The service life of the battery is three years, after which time the battery must be
replaced. See the storage-management software for information on how to view and
set the battery expiration date.
Each RAID controller has a green Battery LED on the back that indicates the
battery status, as follows:
v The LED is on and remains steady when the battery is fully charged.
v The LED flashes when the battery is charging or performing a self-test.
v The LED is off if the battery or the battery charger has failed.
Cache
active
LED
Chapter 4. Operating the storage server
55
Advertisement
Table of Contents
