Re: [libvirt] [RFC PATCH] libvirt support to force convergence of live guest migration

On 11/26/2013 4:24 AM, Jiri Denemark wrote: > On Thu, Nov 21, 2013 at 17:47:24 -0800, Chegu Vinod wrote: >> Busy enterprise workloads hosted on large sized VM's tend to dirty >> memory faster than the transfer rate achieved via live guest migration. >> Despite some good recent improvements (& using dedicated 10Gig NICs >> between hosts) the live migration may NOT converge. >> >> Recently support was added in qemu (version 1.6) to allow a user to >> choose if they wish to force convergence of their migration via a >> new migration capability : "auto-converge". This feature allows for qemu >> to auto-detect lack of convergence and trigger a throttle-down of the >> VCPUs. >> >> This RFC patch includes the libvirt support needed to trigger this >> feature. (Testing is still in progress)

> So except for the small issues, the patch looks good to me. However, do > I remember correctly that this feature can be turned on dynamically for > an already running migration? If so, I think we want a second patch > adding a new API for setting this auto-converge feature. Yes. Is there a sample reference/example that I could look up ?