This was a lovely "bug" to run into during a server migration tonight.
as root: grep -r / foobar
cause a new system to crash/reboot. Did it again and it did it exactly at the same place.
The last line was about not being able to read (or some similar error) /dev/watchdog
Rackspace thought it was a bug too, and quite odd, then they looked around and decided this is "normal" when watchdogs are turned on. Huh? I haven't bz-checked this yet, but this smells funny to me. A read of a file should never *trigger* an action, right? It's like a /sys file: you echo > to them to get it to do something, never *read*.
Any thoughts? If I don't find a bz about it, I'm definitely going to make one. (RHEL6)
RS claims the only "fix" is to disable watchdog or make sure not to grep -r /.
I know grep -r / is really cheesy and lame-o and wasteful as there's not going to be something in /dev I'll need (and reading /dem/kmem is really cheesy) but sometimes I really need to find all occurences of something fast with the least hassle possible (not going into / and ls'ing and deciding what to include/exclude which is different on many systems). My point is, grep -r / has never given me trouble in the past 20 years, but then again I usually don't have a watchdog.