HP StorageWorks 2000fc G2 Modular Smart Array - Manual (Page 20)

20 Components
CAUTION: To preserve the existing data stored in the CompactFlash, you must transport the
CompactFlash from the failed controller to the replacement controller using a procedure outlined in the HP
StorageWorks 2312fc/2324fc controller replacement instructions, shipped with the replacement controller.
Failure to use this procedure will result in the loss of data stored in the cache module. The CompactFlash
must stay with the same enclosure. If the CompactFlash is used/installed in a different enclosure, data
loss/data corruption will occur.
IMPORTANT: In dual controller configurations, there is no need to transport a failed controller’s cache to
a replacement controller because the cache is duplicated between the controllers.
Super-capacitor pack
To protect RAID controller cache in case of power failure, the MSA2312fc and MSA2324fc are equipped
with super-capacitor technology. The super-capacitor pack and CompactFlash memory in each controller
module provide unlimited cache memory backup time. The super-capacitor pack provides energy for
backing up unwritten data in the write cache to the CompactFlash in the event of a power failure. Unwritten
data in CompactFlash memory is automatically committed to disk media when power is restored. While
the cache is being maintained by the super-capacitor, the Cache Status LED flashes at a rate of 1/10
second on and 9/10 second off.