Re: [libvirt] [BUG] libvirtd on destination crash frequently while migrating vms concurrently

-----Original Message----- From: Michal Privoznik [mailto:mprivozn@redhat.com] Sent: Friday, October 11, 2013 8:58 PM To: Wangyufei (A) Cc: libvir-list(a)redhat.com; jdenemar(a)redhat.com; Wangrui (K) Subject: Re: [libvirt] [BUG] libvirtd on destination crash frequently while migrating vms concurrently On 27.09.2013 09:55, Wangyufei (A) wrote: > Hello, > I found a problem that libvirtd on destination crash frequently while > migrating vms concurrently. For example, if I migrate 10 vms > concurrently ceaselessly, then after about 30 minutes the libvirtd on > destination will crash. So I analyzed and found two bugs during > migration process. > First, during migration prepare phase on destination, libvirtd assigns > ports to qemu to be startd on destination. But the port increase > operation is not aomic, so there's a chance that multi vms get the same > port, and only the first one can start successfully, others will fail to > start. I've applied a patch to solve this bug, and I test it, it works > well. If only this bug exists, libvirtd will not crash. The second bug > is fatal. > Second, I found the libvirtd crash because of segment fault which is > produced by accessing vm released. Apparently it's caused by > multi-thread operation, thread A access vm data which has released by > thread B. At last I proved my thought right. So I've just pushed the patch upstream. Please give it a try if it resolves your problem. Michal