What is a write cache battery?
These batteries are used to protect the contents of a hardware RAID card’s write cache from being lost, in the event of a power-outage.
What does a server cache battery do?
Quite simply, the cache buffer speeds up data from the processor to the disk. And this cache buffer has a battery to keep the data in the cache buffer safe until it gets written to the disk drives. As this battery loses power, you will get a warning message on your console to notify your service provider.
What happens when the RAID battery fails?
If the battery is bad then the RAID controller would either be bypassing cache and writing directly or using cache while complaining about possible data integrity/loss in the event of an unexpected power event.
What is flash back write cache?
The Flash Backed Write Cache (FBWC) uses flash devices to retain cache data and super-capacitors (super-caps) instead of batteries to provide power during a power loss.
Does a RAID controller need a battery?
Everyone knows that RAID controller batteries need to be replaced at regular intervals. That is one of the key drivers towards supercapacitors on RAID cards.
How does RAID cache work?
Built into the RAID controller is a buffer. The buffer “tells” the processor that the “data write-to-disk” is complete, so the system “knows” to go back to the processor to fetch more data to send to the disks. Quite simply, the cache buffer speeds up data from the processor to the disk.
How long do RAID batteries last?
With these BBU kits, the 12-hour data retention time setting should yield a 3-5 year replacement cycle.
What does the HP Smart Storage battery do?
HPE Smart Storage Batteries provide backup power to Smart Array Cache and NVDIMMs in the event a server power failure. The backup power is provided for up to 2 minutes, which allows data in volatile memory (DIMM) to be stored to non-volatile memory (flash).
What is FBWC module?
FBWC is a flash based cache module that does not have the battery limitation of how long it can retain what is written to the module.
