On Sat, Sep 6, 2014 at 3:05 AM, Andrey Korolyov <and...@xdel.ru> wrote: > On Sat, Sep 6, 2014 at 2:14 AM, Paolo Bonzini <pbonz...@redhat.com> wrote: >> Il 05/09/2014 21:35, Andrey Korolyov ha scritto: >>> - boot up a VM, make sure to feed it heavy long task, for example >>> kernel compilation, >>> - neither migrate once in the middle of process (with fallback to >>> non-live migration which is available in libvirt, else it may take >>> forever) or just wait up to the end, >>> - live migration time degrades from sub-10s value to larger values >>> forever, not regarding if workload is still presented or not. >> >> Are you sure you aren't simply doing migration with a low bandwidth >> limit (the default is 32 MB/s), and moving over a gigabyte worth of page >> cache data to the new machine? >> >> Paolo > > As far as I can see setspeed does not change anything over stdev > variation for gigabit, but rss size does. Will check if this part is > actually broken, because we are overriding default speed value every > time and if it started being constant, it may explain such a > difference.
The mess was caused by libvirt which sets migration bandwidth to 8 EB/s, so process took shorter times when I expect from it to utilize some percent of server interconnection bandwidth.
