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
Received on Thu Dec 09 2004 - 09:53:15 MST
This archive was generated by hypermail pre-2.1.9 : Sat Jan 01 2005 - 12:00:02 MST