On Wed, Oct 13, 2010 at 8:26 PM, Eugene Vilensky <[email protected]> wrote: > On Tue, Oct 12, 2010 at 10:24 AM, Tino Schwarze > <[email protected]> wrote: >> On Tue, Oct 12, 2010 at 02:57:56PM +0000, Jefferson Ogata wrote: >>> On 2010-10-12 14:52, Tino Schwarze wrote: >>> > I suppose(!) alignment doesn't matter that much (or at all) for RAID10 >>> > (which is the right choice for DB loads with only few disks). >>> > >>> > But that's just my gut feeling. >>> >>> My gut thinks your gut is wrong about that. :^) Why would RAID10 be >>> exempt? The PERC is still going to bunch up disk addressing into RAID >>> chunks. If your filesystem blocks aren't aligned with the chunk >>> boundaries, you're going to need two disks to seek to satisfy some read >>> requests, and four disks for some write requests. >> >> Right. These disks could be doing other stuff instead of reading one >> another RAID chunk. >> >> So better always align to stripe size. > > I take it Anaconda's cylinder 63 default, and Windows 2003's 32,256 > bytes are no good. 2008/Vista uses a 1 MB offset on a GPT label, so > we should be good there since it'll cleanly divide by any reasonable > stripe size? > > Thanks for the tips everyone. >
One more question...is there anything to be concerned about regarding on disk geometry or does the PERC do the right thing automatically when using OEM drives? _______________________________________________ Linux-PowerEdge mailing list [email protected] https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq
