[libvirt-users] "virsh list" hangs

[Yunchih Chen]

On 02/21/2017 12:07 PM, 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 at 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 at 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 at vm-host:~# strace -o /tmp/trace -e trace=network,file,poll virsh
>>> list  # hangs forever .....
>>> ^C
>>> root at 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 at 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 at 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)
>
> Thanks for your help : )
>
> [1] https://www.csie.ntu.edu.tw/~yunchih/s/gdb-full-trace.txt
>
Any update on this?  What other debug info could I provide?

I just enable libvirtd's debug option and here[1] is the output.

[1] https://www.csie.ntu.edu.tw/~yunchih/s/libvirtd-debug.log


-- 
--
Yun-Chih Chen 陳耘志
Network/Workstation Assistant
Dept. of Computer Science and Information Engineering
National Taiwan University
Tel: +886-2-33664888 ext. 217/204
Email: ta217 at csie.ntu.edu.tw
Website: http://wslab.csie.ntu.edu.tw/