> Hi, Hi A'rpi, nice to see you there :) > I've spent few hours experiencing with the watchdog feature of the > Fujitsu Siemens server board (don't ask the model name, what i know is > that it uses serverworks CSB5 chipset) using lm_sensors 2.7.0's fscscy > driver.(I needed it because i have random hangup (once a week, so hard > to debug...) on a server). > > Ok, so there is /proc/sys/dev/sensors/fscscy-i2c-0-73/wdog, containing > 3 0..255 values for the 3 watchdog registers. > > The first one is the time counter, it counts backwards (seems > write-only, at least you can't read the current counter back). It's in > 2 seconds base, so writting 30 there means 60 seconds delay. It seems > whole 0..255 range is supported, so up to 510 seconds. writting 0 > means immediate hardware reset. According to the docs, this is read and write. I'll check the code and update if required. > The second number is unknown to me, it > doesn't matter what value i put there. According to the docs again, it is supposed to be a "state" register, so it's probably meant to be read from, not written to (also the same docs say it's read and write). > The third is the control > register, with flags 16, 32 and 128. If i write only 16 or 144 > (128+16), it means system reset when the counter reaches 0. If i OR > 32, it has no effect. Do you mean that the 6th bit has no effect, or that setting it to 1 disables the watchdog? > So, the world's simples watchdog using this mainboard: > > while true ; do > echo 30 0 16 > /proc/sys/dev/sensors/fscscy-i2c-0-73/wdog > sleep 10 > done > > it does hardware reset after 1 minutes, if this script is killed or > system hangup occurs. > > Also note, that BIOS has a strange setting, named OS Boot Retry Count, > set to 0 by default, it changes watchdog behaviour to power off > instead of reset.(0=poweroff 1..7=reset). It took me a while to find > this... Thanks for reporting your experience (and success). Never used a watchdog myself, but I know how it works and your explanations make sense. > Please add the above to the documentation (doc/chips/fscscy), so i can > save a few hours of resetting for other people :) It will be done :) -- Jean Delvare http://www.ensicaen.ismra.fr/~delvare/
