RAID controllers with cache protection

Cache protection

— cache protection is necessary for preserving data that has already entered the cache but has not yet been written to the disks. Typically, a battery or supercapacitor is used for this purpose: in the event of a power failure, they help the controller avoid losing incomplete write operations.

This function is especially important when the write-back cache is enabled, where the speed is higher, but some data is temporarily stored in the controller's memory. Without protection, a sudden power outage can lead to data loss or array damage.