SUSE Linux Enterprise Server (kernel version 3.0.101 onwards) have stopped the automatic loading of watchdog drivers and this system change has an impact on Sentinel high availability implementations. After upgrading to a kernel version that includes this change, the cluster services do not come up automatically after the system boots because the watchdog driver may not be auto loaded.
All customers who have implemented high availability with SUSE Linux Enterprise Server should contact their hardware vendor to identify the recommended watchdog driver for their Sentinel server and follow these steps:
Modify /etc/init.d/boot.local to include the following line. Then either reboot your machine or run the command once to load the driver immediately.
/sbin/modprobe -v --ignore-install "watchdog driver"
Recent kernel upgrades of SUSE Linux Enterprise Server (kernel version 3.0.101 onwards) have stopped the automatic loading of watchdog drivers. Previously, when sbd opened /dev/watchdog (if no driver was loaded yet) the kernel would auto load everything that could possibly serve as a watchdog driver and stick to the first one that didn't fail to load. This did not work properly. SUSE recommends that customers identify the watchdog driver recommended by their hardware vendor. Then check whether it has been loaded by doing the following:
lsmod | grep <watchdog driver>
If it auto loads, it should be present in the output. If it isn't present, it should be added to the start script on the operating system as directed in the resolution section.
The SUSE Linux Enterprise Server team recommends the following site for more information: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/watchdog/Kconfig. You can look at the Makefile to map kernel configuration symbols to driver names as needed.
Although it is generally better to use hardware specific drivers on physical hardware, there is also a universal watchdog driver called softdog that might offer enough safety margin for your needs. NetIQ recommends that you contact your hardware vendor for more guidance.