> There's been some discussion the last few days about the merits of HW > vs SW raid on the Backuppc support mailing list. It seems to be a not > quite religious issue, maybe not up to the level of vi vs. emacs.
Yes, there certainly are some strong opinions on both sides of the issue. > > Just how much performance penalty is there in SW raid? As a semi-random statistic, I have a db server with a 7 (scsi) disk array attached, software raid5. Bonnie tests gave read&write performance ~= writing to a single local scsci disk (so I suspect the bottleneck there is the bus itself). I've seen the raid process eat 5-7% of the cpu on the box during large queries (bearing in mind this isn't a particularly strong box by current standards - Dell 1650). Am I prepared to eat ~5% cpu to use software raid on this box - yes - I'm not going to notice 5%. Also presumably this penalty would represent an even smaller percentage on a stronger box. David -- TriLUG mailing list : http://www.trilug.org/mailman/listinfo/trilug TriLUG Organizational FAQ : http://trilug.org/faq/ TriLUG Member Services FAQ : http://members.trilug.org/services_faq/
