On 12/03/2009 03:08 AM, Grant McWilliams wrote: > > Personally, I never touch raid5, but then, I'm on sata. I do agree > that there are benifits to hardware raid with battery backed cache if > you do use raid5 (but I think raid5 is usually a mistake, unless it's > all read only, in which case you are better off using main memory for > cache. you are trading away small write performance to get space; > with > disk, space is cheap and performance is expensive, so personally, if > I'm going to trade I will trade in the other direction.) > > > Interesting thoughts on raid5 although I doubt many would agree. I > don't see how the drive > type has ANYTHING to do with the RAID level. There are different RAID > levels for different situations > I guess but a RAID 10 (or 0+1) will never reach the write or read > performance > <http://www.tomshardware.com/reviews/external-raid-storage,1922-9.html> > of a RAID-5. The disk space waste > isn't too much of a problem anymore because as you say drives are > getting much cheaper. Although on that subject > I'll mention that enterprise drives and desktop drives are NOT the > same thing. We deal in hundreds of drives and see > about a 3% failure on desktop drives and only a fraction of that on > enterprise drives. > > I will say though that in my opinion the one really important thing to > consider is the price. These controllers > aren't cheap and if you skimp you will pay. For sequential single > reads (streaming one stream) I'd consider > using a software "RAID" 0. For a mirror I'd consider Software RAID but > once I get serious and go for RAID5 or RAID6 I'd > only use Hardware RAID. and none of this options is the answer to the problem "FakeRaid or Software Raid" :))