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On Thu, 27 Nov 2008, James Fidell wrote: > Gordon Henderson wrote: > >> Going to RAID-0 will in-theory double your disk bandwidth. It'll also >> double the chances of failure, now that you need to rely on 2 drives for >> the data. RAID-1 will not give yo any speed-up whatsoever. (Actually the >> Linux R1 driver may give you a speed-up, but not by much) > > I've not looked at how MD or LVM does it, but in theory RAID1 can give > you a good increase in speed because reads from the two (usually) > mirrored drives can be interlaced. In theory, yes. However what you need to do is predict the next block to be read then alternate reads from each drive... This may work for streamed data. There was a lot of talk about this on the Linux-Raid list some years back and I don't think anything came of it. The Linux RAID driver will read alternative chunks off each drive, but this won't neccessarilly give you a speed-up, and may actually defeat a drives own read-ahead and buffering logic. RAID-0 for speed. RAID-10 for speed and redundancy. My newest box is nearing completion, I'll post some crude benchmarks soon... Gordon -- The Mailing List for the Devon & Cornwall LUG http://mailman.dclug.org.uk/listinfo/list FAQ: http://www.dcglug.org.uk/linux_adm/list-faq.html