Linode Forum

[ronsoriano]

Hi, I open a ticket lately regarding my frequent restart on my Linode. The tech support told me that it might cause of Kernel Panic. How do I know if my server has this kind of setting?

[NeonNero]

"Kernel panic" is the Linux equivalent of a Windows "Blue Screen of Death" - meaning, an unrecoverable system error.
http://en.wikipedia.org/wiki/Kernel_panic

When it happens, the system will have to be restarted (or in the case of virtual machines, your particular instance has to be rebooted).

[obs]

If you log into lish you should see a panic message on the console screen. Otherwise check your /var/log/syslog or /var/log/messages for kernel related issues (it'll say kernel next to the message).

It could just be a case you're running out of ram and your server is locking up. Can provide more details about the restarts i.e. do they happen automatically or are you doing it manually?

[ronsoriano]

It happens automatically, but my ram only consumes 40% I'm using plan 768. How can I stop this?

[obs]

You probably want it to reboot automatically on a kernel panic (if it is a kernel panic) otherwise the server will just stop working.

Log into lish, type logview and paste the contents here. Then we will see if it is a kernel panic.

[ronsoriano]

I typed in "logview" but it seems its not the right command? I'm sorry I still new to Linux regarding this problems.

[obs]

Have a read of this http://library.linode.com/troubleshooting/using-lish-the-linode-shell it tells you how to use lish including the logview command

[ronsoriano]

When I try to login now via LISH, my screen went crazy.

[obs]

Are you using lish via ssh or your browser? If via your browser use ssh it's better. If not define "crazy"

[ronsoriano]

It pops out too many words. But after few minutes, the screen froze stating that Console starting... but I can't type anything.. .Should I wait on this to boot?

[ronsoriano]

I'm using PuTTy.

[obs]

Try pressing ctrl+a then keep ctrl held down and press d

If that doesn't work raise a ticket with linode support to see if there's something wrong with your lish.

[ronsoriano]

Alright, here's what I got from logview

Code: top - 18:23:45 up 26 min,  1 user,  load average: 0.09, 0.04, 0.05
Tasks:  99 total,   1 running,  98 sleeping,   0 stopped,   0 zombie
Cpu(s):  0.0%us,  0.1%sy,  0.0%ni, 99.8%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:    768512k total,   480788k used,   287724k free,    10716k buffers
Swap:   524284k total,        0k used,   524284k free,   152604k cached

Broadcast message from root (Fri Nov 25 18:23:47 2011):IME+  COMMAND
 6137 root      20   0  264m 242m 2716 S  0.7 32.3   0:06.38 map-server_sql
The system is going down for system halt NOW!  0.1   0:00.14 top
INIT: Switching to runlevel: 0616  528 S  0.0  0.1   0:00.46 init
INIT: Sending processes the TERM signalS  0.0  0.0   0:00.00 kthreadd
    3 root      20   0     0    0    0 S  0.0  0.0   0:00.00 ksoftirqd/0
    4 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kworker/0:0
    5 root      20   0     0    0    0 S  0.0  0.0   0:00.03 kworker/u:0
    6 root      RT   0     0    0    0 S  0.0  0.0   0:00.00 migration/0
    7 root      RT   0     0    0    0 S  0.0  0.0   0:00.00 migration/1
    8 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kworker/1:0
    9 root      20   0     0    0    0 S  0.0  0.0   0:00.00 ksoftirqd/1
   10 root      RT   0     0    0    0 S  0.0  0.0   0:00.00 migration/2
   11 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kworker/2:0
   12 root      20   0     0    0    0 S  0.0  0.0   0:00.00 ksoftirqd/2
   13 root      RT   0     0    0    0 S  0.0  0.0   0:00.00 migration/3
   14 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kworker/3:0
   15 root      20   0     0    0    0 S  0.0  0.0   0:00.00 ksoftirqd/3
Stopping yum-updatesd: [  OK  ]
Stopping atd: [  OK  ]
Shutting down console mouse services: [  OK  ]
Stopping httpd: [  OK  ]
Stopping sshd: [  OK  ]
Shutting down sm-client: [  OK  ]
Shutting down sendmail: [  OK  ]
Stopping MySQL:  [  OK  ]
Stopping crond: [  OK  ]
Stopping autofs:  Stopping automount: [  OK  ]
[  OK  ]
Shutting down ntpd: [  OK  ]
Stopping system message bus: [  OK  ]
Stopping auditd: type=1305 audit(1322216636.690:29): audit_pid=0 old=2968 auid=4                                                                                       294967295 ses=4294967295 res=1
[  OK  ]
Shutting down kernel logger: [  OK  ]
Shutting down system logger: [  OK  ]
find: /sys/class/iscsi_session/: No such file or directory
Shutting down interface eth0:  [  OK  ]
Shutting down loopback interface:  [  OK  ]
Flushing firewall rules: type=1325 audit(1322216639.046:30): table=security fami                                                                                       ly=2 entries=4
type=1300 audit(1322216639.046:30): arch=40000003 syscall=102 success=yes exit=0                                                                                        a0=e a1=bfe036e0 a2=8055884 a3=8e186a4 items=0 ppid=7545 pid=7554 auid=42949672                                                                                       95 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=429496                                                                                       7295 comm="iptables" exe="/sbin/iptables" key=(null)
type=1325 audit(1322216639.051:31): table=security family=2 entries=4
type=1300 audit(1322216639.051:31): arch=40000003 syscall=102 success=yes exit=0                                                                                        a0=e a1=bf98e560 a2=8055884 a3=9f886a4 items=0 ppid=7545 pid=7556 auid=42949672                                                                                       95 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=429496                                                                                       7295 comm="iptables" exe="/sbin/iptables" key=(null)
type=1325 audit(1322216639.053:32): table=raw family=2 entries=3
type=1300 audit(1322216639.053:32): arch=40000003 syscall=102 success=yes exit=0                                                                                        a0=e a1=bf84ae60 a2=8055884 a3=90ea508 items=0 ppid=7545 pid=7557 auid=42949672                                                                                       95 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=429496                                                                                       7295 comm="iptables" exe="/sbin/iptables" key=(null)
type=1325 audit(1322216639.057:33): table=raw family=2 entries=3
type=1300 audit(1322216639.057:33): arch=40000003 syscall=102 success=yes exit=0                                                                                        a0=e a1=bfd3fab0 a2=8055884 a3=95e6508 items=0 ppid=7545 pid=7559 auid=42949672                                                                                       95 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=429496                                                                                       7295 comm="iptables" exe="/sbin/iptables" key=(null)
type=1325 audit(1322216639.060:34): table=nat family=2 entries=5
[  OK  ]
Setting chains to policy ACCEPT: security raw nat mangle filter [FAILED]
Unloading iptables modules: [  OK  ]
Starting killall:  [  OK  ]
Sending all processes the TERM signal...
Sending all processes the KILL signal...
Saving random seed:
 enable [-pnds] [-a] [-f filename]  eval [arg ...]
 xec [-cl] [-a name] file [redirec exit [n]
 xport [-nf] [name[=value] ...] or false
 c [-e ename] [-nlr] [first] [last fg [job_spec]
 or NAME [in WORDS ... ;] do COMMA for (( exp1; exp2; exp3 )); do COM
 unction NAME { COMMANDS ; } or NA getopts optstring name [arg]
 ash [-lr] [-p pathname] [-dt] [na help [-s] [pattern ...]
history [-c] [-d offset] [n] or hi if COMMANDS; then COMMANDS; [ elif
Syncing hardware clock to system time audit_printk_skb: 111 callbacks suppressed
 ype=1111 audit(1322216645.953:53): local name[=value] ...id=4294967295 ses=4294                                                                                        ogout msg='changing system time: expopd [+N | -N] [-n]hostname=?, addr=?, termi                                                                                        rintf [-v var] format [arguments] pushd [dir | +N | -N] [-n]
 wd [-LP]                           read [-ers] [-u fd] [-t timeout] [
 eadonly [-af] [name[=value] ...]  return [n]
 elect NAME [in WORDS ... ;] do CO set [--abefhkmnptuvxBCHP] [-o opti
 hift [n]lted.                      shopt [-pqsu] [-o long-option] opt
 ource filename [arguments]         suspend [-f]
 est [expr]t 100 lines from current time [-p] PIPELINE
 imes-------------------------------trap [-lp] [arg signal_spec ...]
 ruetion NAME { COMMANDS ; } or NA gtype [-afptP] name [name ...]
 ypeset [-afFirtx] [-p] name[=valu ulimit [-SHacdfilmnpqstuvx] [limit
 mask [-p] [-S] [mode]t] [n] or hi iunalias [-a] name [name ...] elif
 nset [-f] [-v] [name ...]] or job kuntil COMMANDS; do COMMANDS; done
variables - Some variable names an wait [n]
 enable [-pnds] [-a] [-f filename]  eval [arg ...]
 xec [-cl] [-a name] file [redirec exit [n]
 xport [-nf] [name[=value] ...] or false
 c [-e ename] [-nlr] [first] [last fg [job_spec]
 or NAME [in WORDS ... ;] do COMMA for (( exp1; exp2; exp3 )); do COM
 unction NAME { COMMANDS ; } or NA getopts optstring name [arg]
 ash [-lr] [-p pathname] [-dt] [na help [-s] [pattern ...]
 istory [-c] [-d offset] [n] or hi if COMMANDS; then COMMANDS; [ elif
 enable [-pnds] [-a] [-f filename]  eval [arg ...]
 xec [-cl] [-a name] file [redirec exit [n]
 xport [-nf] [name[=value] ...] or false
 c [-e ename] [-nlr] [first] [last fg [job_spec]
 or NAME [in WORDS ... ;] do COMMA for (( exp1; exp2; exp3 )); do COM
 unction NAME { COMMANDS ; } or NA getopts optstring name [arg]
 ash [-lr] [-p pathname] [-dt] [na help [-s] [pattern ...]
history [-c] [-d offset] [n] or hi if COMMANDS; then COMMANDS; [ elif
 obs [-lnprs] [jobspec ...] or job kill [-s sigspec | -n signum | -si
 et arg [arg ...]                   local name[=value] ...
 ogout                              popd [+N | -N] [-n]
 rintf [-v var] format [arguments] pushd [dir | +N | -N] [-n]
 wd [-LP]                           read [-ers] [-u fd] [-t timeout] [
 eadonly [-af] [name[=value] ...]  return [n]
 elect NAME [in WORDS ... ;] do CO set [--abefhkmnptuvxBCHP] [-o opti
 hift [n]                           shopt [-pqsu] [-o long-option] opt
 ource filename [arguments]         suspend [-f]
 est [expr]                         time [-p] PIPELINE
 imes                               trap [-lp] [arg signal_spec ...]
 rue                                type [-afptP] name [name ...]
 ypeset [-afFirtx] [-p] name[=valu ulimit [-SHacdfilmnpqstuvx] [limit
 mask [-p] [-S] [mode]              unalias [-a] name [name ...]
 nset [-f] [-v] [name ...]          until COMMANDS; do COMMANDS; done
variables - Some variable names an wait [n]
 enable [-pnds] [-a] [-f filename]  eval [arg ...]
 xec [-cl] [-a name] file [redirec exit [n]
 xport [-nf] [name[=value] ...] or false
 c [-e ename] [-nlr] [first] [last fg [job_spec]
 or NAME [in WORDS ... ;] do COMMA for (( exp1; exp2; exp3 )); do COM
 unction NAME { COMMANDS ; } or NA getopts optstring name [arg]
 ash [-lr] [-p pathname] [-dt] [na help [-s] [pattern ...]
 istory [-c] [-d offset] [n] or hi if COMMANDS; then COMMANDS; [ elif
 obs [-lnprs] [jobspec ...] or job kill [-s sigspec | -n signum | -si
 et arg [arg ...]                   local name[=value] ...
 ogout                              popd [+N | -N] [-n]
 rintf [-v var] format [arguments] pushd [dir | +N | -N] [-n]
 wd [-LP]                           read [-ers] [-u fd] [-t timeout] [
 eadonly [-af] [name[=value] ...]  return [n]
 elect NAME [in WORDS ... ;] do CO set [--abefhkmnptuvxBCHP] [-o opti
 hift [n]                           shopt [-pqsu] [-o long-option] opt
 ource filename [arguments]         suspend [-f]
 est [expr]                         time [-p] PIPELINE
 imes                               trap [-lp] [arg signal_spec ...]
 rue                                type [-afptP] name [name ...]
 ypeset [-afFirtx] [-p] name[=valu ulimit [-SHacdfilmnpqstuvx] [limit
 mask [-p] [-S] [mode]              unalias [-a] name [name ...]
 nset [-f] [-v] [name ...]          until COMMANDS; do COMMANDS; done
variables - Some variable names an wait [n]
 while COMMANDS; do COMMANDS; done  { COMMANDS ;

[obs]

It's not a kernel panic, something sent your server the shutdown command.

Broadcast message from root (Fri Nov 25 18:23:47 2011)
The system is going down for system halt NOW

So either a cron job, someone logged in via ssh or some other root process sent the signal.

[ronsoriano]

It's impossible that someone know my linode, but cron job is something I should look, and another noob question. How do I know what are cron jobs in my linode?