Intel AXXRSBBU8, Руководство пользователя

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Intel
®
RAID Smart Battery AXXRSBBU8 User’s Guide 1
1
About the Intel
®
RAID Smart Battery
AXXRSBBU8
Intel
®
RAID (Redundant Array of Inexpensive Disks) Controllers and Intel
®
Integrated
RAID Modules provide reliability, high performance, and fault-tolerant disk subsystem
management. A complete fault-tolerant strategy requires protection of all data, including
the unwritten cached data in the RAM cache. If power is lost, the data in the RAM cache
is lost. To avoid data loss, a battery can be added to supply power to the RAID RAM
during an AC power outage or if the AC power cord is removed.
A battery backup unit (BBU) protects the integrity of the cached data on Intel
®
RAID
Controllers by providing backup power if there is a complete AC power failure or a brief
power outage. The Intel
®
RAID Smart Battery Backup Unit provides an inexpensive
alternative to using an uninterruptible power supply (UPS) or it can act as a second level
of fault tolerance when used with a UPS.
The cache memory available on Intel
®
RAID controllers can improve the overall system
performance. Writing data to the controller's cache memory is much faster than writing it
to a storage device. Write operations appear to complete very quickly at the software
application level. The Intel
®
RAID Controller writes the cached data to the storage device
when system activity is low or when the cache is getting full. The risk of using write-back
cache is that the cached data can be lost if the AC power fails before it is written to the
storage device. This risk factor is eliminated when the Intel
®
RAID Controller has a
BBU installed.
The Intel
®
RAID Smart Battery Backup Unit monitors the voltage level of the DRAM
modules installed on the Intel
®
RAID Controller. If the voltage drops below a predefined
level, the battery backup module switches the memory power source from the controller to
the battery pack attached to the Intel
®
RAID Smart Battery Backup Unit. As long as the
voltage level stays below the predefined value, the battery backup module provides power
for memory. When the voltage level returns to an acceptable level, the module switches
the power source back to the Intel
®
RAID Controller, and all pending writes to storage
devices are completed without losing any data.
The battery backup module has built-in functionality to charge the battery pack
automatically and to communicate battery status information such as voltage,
temperature, and current to the host computer system.
The Intel
®
RAID Smart Battery AXXRSBBU8 is a smart battery backup module and uses
lithium-ion (Li-Ion) battery technology. It is compatible with a backup auxiliary power
source. The battery is charged automatically.