On Tue, Oct 12, 2010 at 03:37:48PM +0100, Robin Bowes wrote: > On 12/10/10 09:18, Tino Schwarze wrote: > > On Mon, Oct 11, 2010 at 09:33:35PM -0500, Eugene Vilensky wrote: > > > >> What partition offset should one use when trying to align Windows > >> 2003, 2008R2, or RHEL 5 partitions to PERC6i characteristics for best > >> performance? > > > > Any multiple of your RAID volume's stripe size. What is your RAID > > configuration, exactly? IMO, block alignment should only matter for RAID > > levels involving checksums. > > Hmm, this is potentially interesting. > > We're using PERC 6/i with 4 x 10k 2.5" 146GB drives in RAID10. > > I currently do a straight-forward CentOS install onto the logical drive, > creating two partitions, one small one for /boot and the other across > the rest of the disk which I make an lvm PV and slice it up using lvm.
> The main performance bottleneck for us is write performance for MySQL. > > Could I get better performance by doing things differently? 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. If write performance is the bottleneck, you might want to consider an external file system journal (on SSD, preferably). But I've only heard/read that it helps and I don't know about MySQL tuning. Tino. -- "What we nourish flourishes." - "Was wir nähren erblüht." www.tisc.de _______________________________________________ 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
