RAID Array & Server Glossary of Computer Terms (Letter C)

Cache
A temporary storage area for frequently accessed or recently accessed data. Cache is used to speed up data transfer to and from a disk. See also Caching.

Cache Flush
Refers to an operation where all unwritten blocks in a Write-Back Cache are written to the target disk. This operation is necessary before powering down the system.

Cache Line Size
Represents the size of the data “chunk” that will be read or written at one time, and is set in conjunction with stripe size. Under RAID EzAssistTM, the cache line size (also known as Segment Size) should be based on the stripe size you selected. The default segment size for Mylex RAID controllers is 8K. See also Stripe Size.

Caching
Allows data to be stored in a pre-designated area of a disk or RAM. Caching speeds up the operation of RAID systems, disk drives, computers and servers, or other peripheral devices. See also Cache.

Conservative Cache
An operating mode in which system drives configured with the Write-Back Caching policy are treated as though they were configured for Write-Through operation and the cache is flushed.

Consistency Check
A process that verifies the integrity of redundant data. A consistency check on a RAID 1 or RAID 0+1 configuration (mirroring) checks if the data on drives and their mirrored pair are exactly the same. For RAID Level 3 or RAID Level 5, a consistency check calculates the parity from the data written on the disk and compares it to the written parity. A consistency check from Mylex utilities such as Global Array ManagerTM (GAM) or RAID EzAssistTM give the user the ability to have a discrepancy reported and corrected. See also Parity Check.

Controller
An adapter card, RAID controller, or other module that interprets and controls signals between a host and a peripheral device.