Как проследить причину системной перезагрузки?

Я искал ответ здесь, но никакой результат все же. Вот то, что я нашел до сих пор.

$ cd /var/log
$ last -f wtmp.1 reboot
reboot   system boot  3.16.0-30-generi Mon Jun 29 13:38 - 09:44 (1+20:05)   

wtmp.1 begins Mon Jun  1 10:00:20 2015

Я изучаю/var/log/syslog в это время.

Jun 29 13:09:02 gob kernel: [3689185.489489] audit: type=1400 audit(1435608542.127:92018): apparmor="DENIED" operation="ptrace" profile="docker-default" pid=24305 comm="lsof" requested_mask="trace" denied_mask="trace" peer="docker-default"
Jun 29 13:17:01 gob CRON[24566]: (root) CMD (   cd / && run-parts --report /etc/cron.hourly)
Jun 29 13:36:56 gob kernel: [3690860.358447] init: tty4 main process (900) killed by TERM signal
Jun 29 13:36:56 gob kernel: [3690860.358840] init: tty5 main process (904) killed by TERM signal
Jun 29 13:36:56 gob kernel: [3690860.359222] init: tty2 main process (915) killed by TERM signal
Jun 29 13:36:56 gob kernel: [3690860.359602] init: tty3 main process (916) killed by TERM signal
Jun 29 13:36:56 gob kernel: [3690860.359975] init: tty6 main process (919) killed by TERM signal
Jun 29 13:36:57 gob kernel: [3690860.363264] init: cron main process (1028) killed by TERM signal
Jun 29 13:36:57 gob kernel: [3690860.363886] init: tty1 main process (1120) killed by TERM signal
Jun 29 07:48:17 gob rsyslogd: message repeated 48 times: [ [origin software="rsyslogd" swVersion="7.4.4" x-pid="820" x-info="http://www.rsyslog.com"] rsyslogd was HUPed]
Jun 29 13:37:00 gob rsyslogd: [origin software="rsyslogd" swVersion="7.4.4" x-pid="820" x-info="http://www.rsyslog.com"] exiting on signal 15.
Jun 29 13:38:11 gob rsyslogd: [origin software="rsyslogd" swVersion="7.4.4" x-pid="817" x-info="http://www.rsyslog.com"] start
Jun 29 13:38:11 gob rsyslogd: rsyslogd's groupid changed to 104
Jun 29 13:38:11 gob rsyslogd: rsyslogd's userid changed to 101
Jun 29 13:38:11 gob kernel: [    0.000000] Initializing cgroup subsys cpuset
Jun 29 13:38:11 gob kernel: [    0.000000] Initializing cgroup subsys cpu
Jun 29 13:38:11 gob kernel: [    0.000000] Initializing cgroup subsys cpuacct
Jun 29 13:38:11 gob kernel: [    0.000000] Linux version 3.16.0-30-generic (buildd@kissel) (gcc version 4.8.2 (Ubuntu 4.8.2-19ubuntu1) ) #40~14.04.1-Ubuntu SMP Thu Jan 15 17:43:14 UTC 2015 (Ubuntu 3.16.0-30.40~14.04.1-generic 3.16.7-ckt3)
Jun 29 13:38:11 gob kernel: [    0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-3.16.0-30-generic root=UUID=381b59c0-0a2e-4e30-a58e-387621169164 ro quiet splash vt.handoff=7

Действительно ли там что-нибудь является аварийным здесь? Или другие файлы я должен изучить?

Огромное спасибо за справку.