Has anyone written a self-watchdog script and can share the way it was resolved? I have DD-WRT on one of the routers and can make only one startup script. The problem is doesn't get run. If I log on by telnet and start it manually it works great. So I need to add a cron rule to run it, but not run more then once. I was thinking about using:
if [`ps | grep [c]ustom.sh` -gt 1]; then
exit;
else
...
fi
Do you know any other way to do this?
Linux supports several types of watchdog hardware.
Is there a way to detect the available hardware watchdogs and load the appropriate kernel module (and "softdog" as fallback solution)?
I guess, just trying all available kernel modules is not an optimal solution.
EDIT:
I am surprised that modern systems do not have some kind of watchdog timer built into the CPU (at least no module is loaded for an AMD Athlon II). Are hardware watchdogs rare on consumer/prosumer systems?
We've purchased 3 hp proliant dl120 servers. They come with 2 integrated network adapters - HP NC107i PCIe Gigabit Server Adapter which is based on BCM5723.
After Freebsd 9 installation I've discovered a few problems.
After setting up bge0 network interfaces, I've noticed that I was temporarily losing connection with a server for short periods of time. /var/log/messages was filled up with "bge0: watchdog timeout -- resetting" messages.
I've switched to bge1 interface and after a few hours I've noticed that my server froze completely. I tried to do the same on the other server and got the same result.
I'm trying to understand what's going on and can provide more info on request. If anyone could give me a clue if there is a way to fix this problem by patching bge driver or making some tweaks in BIOS ?
Alternatively I could install some linux version on that server instead of freebsd 9 or add discreet intel network adapter.
I need to create watch dog process (will run in linux version 5.x) that look all time on /etc/cluster.cf file
And if the process matches the string: machineA_is_active in the cluster.cf file
Then this process will execute other script
My question is – how to run this process in way that process will up and running all time that Linux is up –
and in case this process is down need to startup this process again
So please advice what the basic structure for this scenario ?
(I will happy if I get real example)
Recently my FreeBSD 8.0 (GENERIC) box was hit with a large amount of requests from an IP in Taiwan, trying to guess passwords and all of that stuff. Anyway, long story short, I noticed at a certain point I couldn't ssh into the box. After logging in directly, I noticed a huge number of password guesses, and the message msk0: watchdog timeout. msk0 referring to my wired ethernet connection.
I brought the interface back up with ifconfig msk0 up, and was successfully able to ping the address of that interface. However, when trying to ping my main router, which the box is directly connected to, it hung. Attempting to ping my external IP address returned a whole bunch of sendto: no buffer space available.
The problem was resolved with a reboot, but obviously this isn't the ideal way to go about it. In the case of something like this happening again, what steps should I take to restore connectivity? I've read that sometimes it can be prevented with watchdog -t 0, but I'm not sure I want to go down that avenue.
When it comes to prophylaxis, is there a way to refuse connections from IPs that have a certain number of failed logins for a certain period of time? For example, 15 failed logons would result in refused connections for the next twelve hours?