On 07/24/2012 06:14 AM, Christian Balzer wrote: >> > Can you help me? Windows VMs have shown the same issue. > That clearly looks like some Xen deficiency or configuration issue, can't > help you with that, sorry. >
That reminds me - I've once heard a talk on just why Xen has I/O performance issues. It's because of the way syscalls are handled among DomU kernel, Dom0 kernel and hypervisor. KVM has advantages there. There's even an experimental hypervisor(?) called Xenner that allows running Xen domains on a KVM host, with better syscall handling than Xen itself. Note that such deficiencies (and/or advantages) usually apply to certain workloads only. I advise to do more than simple throughput tests. If you *do* measure throughput, I believe that you should transfer more data than fits a 3 second window. Finally: hdparm? Isn't that limited to the old IDE kernel drivers? Are you using those? If so - why? Cheers, Felix _______________________________________________ drbd-user mailing list [email protected] http://lists.linbit.com/mailman/listinfo/drbd-user
