Re: [libvirt] [RFC PATCH] qemu: Don't set migration bandwidth if user not specify it.
On Mon, Aug 26, 2013 at 15:30:33 +0800, Li Wei wrote:
Since commit 6cfdeaac("qemu: Migrate at unlimited speed by
default"),
we set an unlimited migration bandwidth unconditionally, this change will
cause problem when doing "--copy-storage-all" migration, qemu will
submit as much block aio request as bandwidth allowed and use too much
memory and finally killed by the oom-killer.
Actually, we should only set migration speed when user specified it,
otherwise, we let qemu use its default settings.
I don't think this is a good idea. QEMU's default migration bandwidth is
very low and IMHO anyone doing migration expects it to run at wire speed
unless they explicitly limit the bandwidth. If it doesn't work with
storage migration (is it using NBD or not?), we may add special handling
for that.
Jirka