In article <[EMAIL PROTECTED]>, Xie, Bill <[EMAIL PROTECTED]> wrote: >All, > >I am testing the multi-threaded IO performance on Opteron servers. > >I use dd as the test tools. The single dd can reach 60MBps for single disk. > >on 2.6.5 kernel, If dd numbers exceed the CPU numbers, vmstat bi reduced >to 20MBps. > >on 2.4.21 kernel, multi-threaded IO performance works fine, even I run >40 dd command at same time. > >Does anybody experienced similar issue also?
First, use a more recent kernel, 2.6.11.x or 2.6.12.x. Then try if changing the I/O scheduler (/sys/block/sda/queue/scheduler) to deadline or cfq makes a difference. I'm using 2.6.11.x and the cfq scheduler on most servers right now. Mike. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
