HP StorageWorks HSG60 and HSG80 Array Controller and Array Controller Software Troubleshooting Guide (EK-G80TS-SA. C01, March 2005)

Troubleshooting Information
46 HSG60 and HSG80 Array Controller and Array Controller Software Troubleshooting Guide
Nonvolatile memory
The controller provides writeback caching for storage units as long as the
controller cache memory is connected to a nonvolatile backup power source, such
as an ECB. The cache module must be nonvolatile to preserve unwritten cache
data during a power failure. If the cache memory is not connected to a backup
power supply, this unwritten data is lost during a power failure.