hahn at physics.mcmaster.ca
Thu Feb 28 16:19:55 PST 2002
> Raid 5 is costly. As I understand it (not very well) there's 3 writes for
> RAID 5. Reading can be slow, but not nearly as bad. Obviously you dont want
I've never quite understood why people think R5 is expensive.
yes, you have to do the parity calculation, and a 1 byte write
does require an update of the parity block for that stripe,
but it's not egregious.
a casually built box, kt266a, via+2xPromise cards, 6x100G WD disks
can sustain 80 MB/s with Linux's raid5. probably higher with tuning.
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