On Thu, 2006-03-02 at 17:19 +0100, Marton Gabor wrote: > Hi! > > Thank you all for the fast replies, you helped me a lot. Unfortunately > we cannot afford a HW RAID card, so I have to make it with software RAID. > Now I have the idea to use RAID5 and if I get the picure rigth I need > let's say a ~100MB /boot in RAID1, 512MB swap not in RAID on every disk, > and I can build a RAID5 from the rest of the storage space, and will be > able to use 750GB-(/boot*4)-(swap*4) and the 4th HD will store the > so-called parity information. Not quite. With Raid3 and Raid4 the parity is stored on an extra disk, so you have: [data][data][data][data][parity]
Raid5 spread the parity across all disks, so loss of any single disk will not cause any data loss. The data on that disk can be rebuilt easily, but two disk failures are fatal. Example for a 4-disk raid5: (d=data, P=parity) 1234 dddP ddPd dPdd Pddd ... So with 4 disks you get 3 capacity, but there is no dedicated place for parity! -- Stand still, and let the rest of the universe move
signature.asc
Description: This is a digitally signed message part
