At 9:06 pm +0100 24/1/01, Aley Keprt wrote: >> > How can it increate a probility of a disk crash? Is it just because of >using >> > two disks? >> > Is so, it is a nonsense. >> >> No. Disks come with a MTBF. If you add disks, this MTBF remains >> (almost) constant. The MTBF of the entire raid will then decrase >> when the number of disks increase. > >I wrote this already, so just for completeness: >Higher data loss probability is caused by usage of two disks. It has nothing >to do with RAID. >If you use two disks without RAID0, you have the same data loss probability.
Wrong. With RAID0, you lose the integrity of your *entire* filesystem when _either_ of the disks crash. So you expect to potentially lose 100% of your data every (MTBF/2) years. Wheras with independent disks, you only lose half your data when one disk crashes. If you say that both disks are expected to crash after MTBF years, then that's already a 2x improvement over RAID0. >Have you ever heard about backuping? I practise this for years, and it >helped me much! Yes, we do this a lot at work. But I daresay that restoring a few terabytes of data would be pretty tedious if we ever needed to do it. Andrew -- --- Andrew Collier ---- ---- http://mnemotech.ucam.org/ --- -- r<2+ T<4* cSEL dMS hEn/CB<BL A4 S+*<++ C$++L/mP W- a-- Vh+seT+ (Cantab) 1.1.4
