Xvfb crashes and my server reboots

Question

I'm trying to use Xvfb on one of my server with the following configuration :

Server : proxmox-ve-2.6.32: 3.4-165 (running kernel: 2.6.32-20-pve
OpenVZ Container : Ubuntu 14.04.3 LTS

When launching this command, my server crash after some minutes :

Xvfb :100 2>/dev/null &
export DISPLAY=:100.0
while true; do import -display :100 -window root /tmp/image.png; done > /home/debug2.log & 
while true; do import -display :100 -window root /tmp/image.png; done > /home/debug2.log & 
while true; do import -display :100 -window root /tmp/image.png; done > /home/debug2.log & 
while true; do import -display :100 -window root /tmp/image.png; done > /home/debug2.log & 
while true; do import -display :100 -window root /tmp/image.png; done > /home/debug2.log & 
while true; do import -display :100 -window root /tmp/image.png; done > /home/debug2.log & 
while true; do import -display :100 -window root /tmp/image.png; done > /home/debug2.log & 
while true; do import -display :100 -window root /tmp/image.png; done > /home/debug2.log & 
while true; do import -display :100 -window root /tmp/image.png; done > /home/debug2.log & 
while true; do import -display :100 -window root /tmp/image.png; done > /home/debug2.log &

I tried with other program that work in Xvfb (xulrunner) and I have the same crash, so I guess the bug come from Xvfb. I tried to reproduce this on an other server (Linux 2.6.32-042stab111.12 #1 SMP Thu Sep 17 11:38:20 MSK 2015 x86_64 x86_64 x86_64 GNU/Linux - Ubuntu 14.04.1 LTS) without any problem.

I don't have any log about this in /var/log. When the server crash, the logs are not written. I remove the cache that the log manager should use when writing logs (*.*;auth,authpriv.none /var/log/syslog), without success.

I asked to my provided to check it wasn't a PSU problem, and it is not.

When crashing, the last top I have (updating it each 0.1sec) is this one (launching 20 capture screen, so the load average of 8 is quite normal) :

top - 06:24:56 up 12 min,  1 user,  load average: 8.56, 7.06, 3.79
Tasks: 115 total,  19 running,  96 sleeping,   0 stopped,   0 zombie
%Cpu(s): 85.7 us, 11.9 sy,  0.0 ni,  2.4 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
KiB Mem:  33554432 total,  1328916 used, 32225516 free,        0 buffers
KiB Swap:  1048576 total,        0 used,  1048576 free.   164940 cached Mem

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND
 6497 root      20   0   78732  16708   2732 R  47.2  0.0   0:00.05 import -display :100 -window root /tmp/image.png
 6490 root      20   0   78736  16688   2712 R  37.7  0.0   0:00.04 import -display :100 -window root /tmp/image.png
 6491 root      20   0   78736  16688   2712 R  37.7  0.0   0:00.04 import -display :100 -window root /tmp/image.png
 6492 root      20   0       0      0      0 R  37.7  0.0   0:00.04 [import]
 6498 root      20   0   78736  16692   2712 R  37.7  0.0   0:00.04 import -display :100 -window root /tmp/image.png
 6486 root      20   0   78736  16676   2712 R  18.9  0.0   0:00.02 import -display :100 -window root /tmp/image.png
 1516 root      20   0   89612  10136   2788 R   9.4  0.0   0:39.06 Xvfb :100 -ac -extension GLX
 6499 root      20   0   76024  15976   2372 R   9.4  0.0   0:00.01 import -display :100 -window root /tmp/image.png
17210 root      20   0   22048   1692   1160 R   9.4  0.0   0:09.06 top
    1 root      20   0   33312   2628   1468 S   0.0  0.0   0:00.14 init
    2 root      20   0       0      0      0 S   0.0  0.0   0:00.00 [kthreadd/100]
    3 root      20   0       0      0      0 S   0.0  0.0   0:00.00 [khelper/100]
  162 root      20   0   19424    852    616 S   0.0  0.0   0:00.01 upstart-udev-bridge --daemon
  187 root      20   0   49216   1420    952 S   0.0  0.0   0:00.00 /lib/systemd/systemd-udevd --daemon
  372 syslog    20   0  184088   1488    960 S   0.0  0.0   0:00.00 rsyslogd
  395 root      20   0   15472    908    432 S   0.0  0.0   0:00.00 upstart-socket-bridge --daemon
  402 root      20   0   15356    720    424 S   0.0  0.0   0:00.00 upstart-file-bridge --daemon
  497 root      20   0   14944   1076    884 S   0.0  0.0   0:00.00 /usr/sbin/xinetd -dontfork -pidfile /var/run/xinetd.pid -stayalive -inetd_compat -inetd_ipv6
  499 root      20   0   61316   3068   2384 S   0.0  0.0   0:00.00 /usr/sbin/sshd -D
  510 root      20   0   23604   1040    784 S   0.0  0.0   0:00.00 cron
  554 bind      20   0  402288  19264   2168 S   0.0  0.1   0:00.01 /usr/sbin/named -u bind
  565 mysql     20   0 2431728  63120   7328 S   0.0  0.2   0:03.90 /usr/sbin/mysqld
  700 root      20   0   25292   1696   1380 S   0.0  0.0   0:00.00 /usr/lib/postfix/master
  707 postfix   20   0   27356   1564   1284 S   0.0  0.0   0:00.00 pickup -l -t unix -u -c
  708 postfix   20   0   27408   1616   1320 S   0.0  0.0   0:00.00 qmgr -l -t unix -u
  738 root      20   0   83556   1156    404 S   0.0  0.0   0:00.00 /usr/sbin/saslauthd -a pam -c -m /var/run/saslauthd -n 2
  739 root      20   0   83556    796     44 S   0.0  0.0   0:00.00 /usr/sbin/saslauthd -a pam -c -m /var/run/saslauthd -n 2

I assume "the server" that "crashes" is the OpenVZ container mentioned, not either the physical server underneath, or xvfb (which, in X diction, would also be called a "server")? — rackandboneman, Nov 10 '15 at 11:09
Do you have another server/vm available at the same site, so you could set up remote logging to preserve the logs? Can you monitor memory/CPU usage (eg by calling free -m and uptime and appending the results to a file after every invocation of that command line)? — rackandboneman, Nov 10 '15 at 11:11
The server is the physical server. It reboots itself. The result of last -x : `root pts/0 xxx Tue Nov 10 05:13 still logged in // runlevel (to lvl 2) 2.6.32-20-pve Tue Nov 10 05:12 - 05:20 (00:08) // reboot system boot 2.6.32-20-pve Tue Nov 10 05:12 - 05:20 (00:08) // root pts/0 xxx Tue Nov 10 04:04 - crash (01:07)` — Kevin, Nov 10 '15 at 11:21
Check with your provider whether a watchdog has been installed on these machines. — rackandboneman, Nov 10 '15 at 11:25
No, they don't install anything besides the minimal operating system. I edited my mesage with the last top received. — Kevin, Nov 10 '15 at 11:33

Xvfb crashes and my server reboots

0 Answers0