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. _______________________________________________ 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
