btd (5/1/2012)
I do agree a well put together document BUT I wish we could get away from the interpretation of RAID. 'inexpensive discs'... The 'I' certainly did not mean inexpensive discs when RAID first came out way back when...'Independent' ... why does the computer world keep changing things when it does not need to, we have plenty of change without it...... and as for 'tables' instead of files.........
My personal recollection is that the "I" did stand for inexpensive. Prior to the days of cheap, large, fast, hard disks one of the key metrics was MTBF (Mean Time Between Failures). In those days a lot of the data was stored "off-line" on tape. When a job ran the operator would mount the tape and the data would be transfered to disk as working storage (sort of a cache).
Disk drive failures on early main frame and mini computers were fairly common. Disks with high MTBF were very expensive. Early RAID configurations used the relatively inexepensive Winchester architecture drives to construct fault-tolerant solutions without breaking the bank on expensive high MTBF drives. At a time when CPU cycles were measured in milliseconds, the added disk write penalties did not seem so bad.