On Tue, Mar 19, 2013 at 05:24:59PM +0100, Thomas Knauth wrote: > lately I've been playing around with qemu's/kvm's suspend (to disk) and > resume. My initial expectation was that both operations are I/O bound. So > it surprised me to see that suspend to disk seems to be CPU-bound. > Suspending a VM with 1.5 GB memory takes 55 seconds. This works out to less > than 30 MB/s. Again, I was expecting to be I/O bound and reach 100 MB/s > (and more). I am talking to qemu/kvm via libvirt. Not sure if this matters. > > I am looking for a hint what the issue could be here. Hopefully with > pointers to the (offending) code.
Hi Thomas, Please provide more details about the issue: Which QEMU or libvirt command are you using to suspend the guest to disk? Why do you say it is CPU-bound? Did you use a tool like vmstat or simply because it does 30 MB/s instead of the expected 100 MB/s? Which versions of libvirt and QEMU are you using? Stefan
