On Mon, 29 Nov 2004, Chris Robertson wrote:
"For applications where fault tolerance is required, and retrieval speeds can be slower than those available from hardware alone, RAID 5 is the best choice. For RAID 5, wider stripes appear to improve both sequential access speed and concurrent access speed for files in this range."
This is incorrect. Retreival speed is very high in RAID 5, both sequencial (large) and random (small). RAID 5 read performance is N-1 (where N is the number of drives). The weakness of RAID 5 is random writes which quickly degrades the performance towards the performance of a single drive.
Raid 5 charateristics in modern RAID-5 implementations:
Sequential read : Very fast Random read : Very fast Sequential write: Very fast, with some CPU overhead if no hardware Random write : Bad
Regarrds Henrik
