Parag Shah writes:
Hi Srinivas, I believe the purpose of RAID is to create a failsafe system. Data is written to multiple disks simultanously. If one disk fails, the system continous to be usable with the other disk. I'm not sure if RAID is meant for performance enhancement. In fact when using RAID there is a slight reduction in performance. I could be wrong about this... guys please correct if so.
RAID is indeed used to create a failsafe system. If one of the array of disks fails the information stored on the erring disk can be reconstructed using the other disks. RAID also leads to performance enhancement in some cases(RAID has different level 0-5), this is particularly true if you have a hardware RAID controller. Some features of RAID can be implemented using software. Examples being mirroring of disk using LVM. Also the capacity of two disks can be concatenated for use as a single disk using LVM. I have written an article for LinuxGazette on LVM. Maybe U will find it useful.
<url> http://www.linuxgazette.com/issue84/vinayak.html </url>
Mirroring can lead to significant improvements in reads (parallel reads) thus reducing disk latency times.
Vinayak Hegde APGDST Student NCST-JUHU