Re: [libvirt-users] "virsh list" hangs

On Tue, Feb 21, 2017 at 12:07:41PM +0800, Yunchih Chen wrote: > On 02/20/2017 09:10 PM, Michal Privoznik wrote: >> On 17.02.2017 17:18, Yunchih Chen wrote: >>> `virsh list` hangs on my server that hosts a bunch of VMs. >>> This might be due to the Debian upgrade I did on Feb 15, which upgrades >>> `libvirt` from 2.4.0-1 to 3.0.0-2. >>> I have tried restarting libvirtd for a few times, without luck. >>> >>> Attached below are some relevant logs; let me know if you need some more >>> for debugging. >>> Thanks for your help!! >>> >>> root@vm-host:~# uname -a >>> Linux vm-host 4.6.0-1-amd64 #1 SMP Debian 4.6.4-1 (2016-07-18) x86_64 >>> GNU/Linux >>> >>> root@vm-host:~# apt-cache policy libvirt-daemon >>> libvirt-daemon: >>> Installed: 3.0.0-2 >>> Candidate: 3.0.0-2 >>> Version table: >>> *** 3.0.0-2 500 >>> 500 http://debian.csie.ntu.edu.tw/debian testing/main amd64 >>> Packages >>> 100 /var/lib/dpkg/status >>> >>> root@vm-host:~# strace -o /tmp/trace -e trace=network,file,poll virsh >>> list # hangs forever ..... >>> ^C >>> root@vm-host:~# tail -10 /tmp/trace >>> access("/etc/libvirt/libvirt.conf", F_OK) = 0 >>> open("/etc/libvirt/libvirt.conf", O_RDONLY) = 5 >>> access("/proc/vz", F_OK) = -1 ENOENT (No such file or >>> directory) >>> socket(AF_UNIX, SOCK_STREAM, 0) = 5 >>> connect(5, {sa_family=AF_UNIX, >>> sun_path="/var/run/libvirt/libvirt-sock"}, 110) = 0 >>> getsockname(5, {sa_family=AF_UNIX}, [128->2]) = 0 >>> poll([{fd=5, events=POLLOUT}, {fd=6, events=POLLIN}], 2, -1) = 1 >>> ([{fd=5, revents=POLLOUT}]) >>> poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}], 2, -1) = ? >>> ERESTART_RESTARTBLOCK (Interrupted by signal) >>> --- SIGINT {si_signo=SIGINT, si_code=SI_KERNEL} --- >>> +++ killed by SIGINT +++ >>> >>> root@vm-host:~# lsof /var/run/libvirt/libvirt-sock # hangs too ... >> This is very suspicious. Looks like the daemon is in some weird state >> and hence virsh is unable to get list of domains. >> >> # ps axf | grep libvirtd >> # gdb -p $(pgrep libvirtd) >> (gdb) t a a bt >> >> if you could run those commands and share the output that might shed >> more light. >> >> Michal > Unfortunately, gdb also hangs when attaching to libvirt .... > > root@vm-host:~# gdb -q -p $(pgrep libvirtd) > Attaching to process 9556 > [New LWP 9557] > [New LWP 9558] > [New LWP 9559] > [New LWP 9560] > [New LWP 9561] > [New LWP 9562] > [New LWP 9563] > [New LWP 9564] > [New LWP 9565] > [New LWP 9566] > [New LWP 9567] > [New LWP 9568] > [New LWP 9569] > [New LWP 9570] > [New LWP 9571] > [New LWP 9572] > ^C^C^C^C^C^C^C^C^C^C^C > > It must be killed with SIGKILL, and libvirtd will die with gdb. > > Here[1] is the output of the following command: > > strace -o /tmp/gdb-full-trace.txt -s 1024 -f gdb -q -p $(pgrep libvirtd) Err, that is useless - you've just straced GDB, not libvirtd You need to strace libvirtd as it starts strace -o libvirt.log -f -s 1000 /usr/sbin/libvirtd Regards, Daniel