[pkg-ntp-maintainers] Bug#600182: ntp: NTP switching from kernel time sync status change 4001 to 0001 caused server to stop responding

[sysadmin]

Package: ntp
Version: 1:4.2.4p4+dfsg-8lenny3
Severity: critical
Justification: breaks the whole system


Hi There,

We've just had an issue were a server became unresponsive after NTP started
switching status as per the daemon log below:

Oct 13 19:15:44 mb ntpd[1966]: kernel time sync status change 4001
Oct 13 20:06:59 mb ntpd[1966]: kernel time sync status change 0001
Oct 13 20:41:09 mb ntpd[1966]: kernel time sync status change 4001
Oct 13 20:58:14 mb ntpd[1966]: kernel time sync status change 0001
Oct 13 21:43:43 mb afpd[5409]: afp_alarm: child timed out
Oct 13 21:43:43 mb afpd[5409]: 44.10KB read, 650.20KB written
Oct 13 21:43:43 mb afpd[5409]: Connection terminated
Oct 13 21:43:43 mb afpd[2052]: server_child[1] 5409 exited 1
Oct 13 21:49:26 mb ntpd[1966]: kernel time sync status change 4001
Oct 13 22:06:30 mb ntpd[1966]: kernel time sync status change 0001
Oct 14 00:06:00 mb ntpd[1966]: kernel time sync status change 4001
Oct 14 00:23:06 mb ntpd[1966]: kernel time sync status change 0001
Oct 14 00:57:16 mb ntpd[1966]: kernel time sync status change 4001
Oct 14 01:48:31 mb ntpd[1966]: kernel time sync status change 0001
Oct 14 02:56:49 mb ntpd[1966]: kernel time sync status change 4001
Oct 14 03:48:02 mb ntpd[1966]: kernel time sync status change 0001
Oct 14 06:38:45 mb ntpd[1966]: kernel time sync status change 4001
Oct 14 08:21:13 mb ntpd[1966]: kernel time sync status change 0001
Oct 14 09:46:37 mb ntpd[1966]: kernel time sync status change 4001
Oct 14 10:03:40 mb ntpd[1966]: kernel time sync status change 0001

Once the server was rebooted, netatalk (afpd) clients could reconnect again.
and SSH connections once again worked.

I'm not 100% sure that NTP caused the issue, as the status changes have been
reported previously without causing unresponsiveness. However there is no other
logs indicating any other failures.

Regards,
Mark



-- System Information:
Debian Release: 5.0.6
  APT prefers stable
  APT policy: (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.26-2-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages ntp depends on:
ii  adduser                 3.110            add and remove users and groups
ii  libc6                   2.7-18lenny4     GNU C Library: Shared libraries
ii  libcap1                 1:1.10-14        support for getting/setting POSIX.
ii  libedit2                2.11~20080614-1  BSD editline and history libraries
ii  libncurses5             5.7+20081213-1   shared libraries for terminal hand
ii  libssl0.9.8             0.9.8g-15+lenny8 SSL shared libraries
ii  lsb-base                3.2-20           Linux Standard Base 3.2 init scrip
ii  netbase                 4.34             Basic TCP/IP networking system

Versions of packages ntp recommends:
ii  perl                     5.10.0-19lenny2 Larry Wall's Practical Extraction 

Versions of packages ntp suggests:
pn  ntp-doc                       <none>     (no description available)

-- no debconf information