Dave Ewart píše v Čt 03. 08. 2006 v 19:31 +0100: > On Thursday, 03.08.2006 at 07:30 -0400, Justin Piszcz wrote: > > > >I have 2 disks in RAID 1 and I expected reading will be approx. 2x > > >faster then a single disk reading because there can be used the same > > >technique as on RAID 0. I tested it with bonnie++. Can linux SW RAID > > >1 read "in stripes" to boost the reading performance? > > > > From my benchmarking on my RAID1 (dual raptor RAID1) it appears it > > reads from one drive or the other. > > It all depends on which disk controllers you're using and their > throughput. > > I have two, separate SATA disks on two different SATA controllers and > read performance in a RAID-1 configuration *is* (nearly) twice that of a > single disk, in many situations. I think I've got the benchmark > statistics somewhere... > > If "it appears it reads from one drive or the other" is the case, then > you probably have a bottleneck somewhere else. Are these disks on the > same controller channel? > > Dave. >
My benchmarks have shown me ~45MB/s both on single drive and SW RAID 1 (so no speed up at all). I have UDMA133 PATA (it can theoretically sustain speed over 100MB/s) controller so I would expect the SW RAID 1 will bring me at least more then 50MB/s when reading, right? David -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
