On 2010-10-12 14:37, Robin Bowes wrote: > 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?
See the partitioning discussion here: http://insights.oetiker.ch/linux/raidoptimization/ You can actually observe this if you're interested. Run dd in this form while you watch the disks during an idle period: dd if=/dev/sda2 of=/dev/null bs=4096 count=1 iflag=direct skip=0 You'll probably see one disk light up. Now increase the skip value one at a time. At a certain point you'll see two disks light up. That's because that 4096-byte block actually resides on two separate RAID chunks. This means that every time you access that chunk, two disks have to seek, instead of one. This reduces your IOPS. _______________________________________________ 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
