All,
I disabled the watchdog completely on a few systems, none of them has rebooted so far.
It’s only 3 days now, but that’s a record on the locations I did this. Can someone else try this and post your findings?
One of those systems ran with a cpu@100% yesterday, this never happened before. It was a system pretty far away from our office, so stupid me rebooted it immediatelly in a panic reaction. Afterwards I realised it was a system with disabled watchdog and I should have taken a supout first…hell! 
I did check the scheduler before the reboot to see if no jobs were stuck or so, but this wasn’t the case.
It concerns me a little that MT support replies to me that the problem isn’t wireless related while everybody sees the opposite.
Disabling the watchdog could maybe lead to a supout which reveals more concerning the problem.
In attachment some cacti graphs, showing cpu usage of that particular system.
kind regards
B
