is a virtual block device
created in RAM
upon which a filesystem
is created. Ramdisk
s are most often used in operating system
installers and applications where a small volatile filesystem is not a limitation (ex
. Coyote Linux
One side effect is that file accesses to a ramdisk are far faster than to a electromechanical disk. The latencies for ramdisks are minimal and random seek penalties are nonexistant. Some specialized applications use a dedicated hardware ramdisk to exploit this phenomenon. Supercomputers sometimes use them for increased speed in reading and writing data sets while many high-end hardware RAID systems use them as a write-back cache to reduce the RAID 5 write penalty.