Bug#777735: systemd: Disk corruption on reboot initiated through systemd

[Michael Biebl]

Am 12.02.2015 um 09:54 schrieb Peter Colberg:
> [   11.473895] systemd[1]: Failed to set timeout to 600s: Invalid argument
> [   11.474649] ib700wdt: WDT device closed unexpectedly.  WDT will not stop!
> 
> Both watchdogs close unexpectedly, but i6300esb immediately resets the
> machine, while ib700wdt allows the machine to continue the shutdown.

So, I think there are two bugs here:
a/ the watchdog driver(s) not accepting timeouts of 600s (or rather
anything > 255s)
b/ the i6300esb watchdog driver resetting the machine if such a timeout
is set.

Arguably, b/ is the more nasty one.
After discussion witch upstream, we came to the conclusion that both
issues should be fixed in the driver/kernel.

I went on and looked what the watchdog package does. Interestingly, it
clamps any timeout value to 254s, thus not hitting this issue.
Apparently, i6300esb is able to deal with such a timeout.

Peter, I therefore recommend you set

 ShutdownWatchdogSec=254s

in /etc/systemd/system.conf as well for the time being. This should be
sufficient to workaround this issue for this buggy driver.
Setting 256s, does indeed trigger the issue, which leads to the
conclusion, that the driver is using a char to hold a time value (0-255).

I wonder, if we should workaround this issue by clamping the timeout to
254s as well in systemd. Upstream was strictly against this though, as
he doesn't want to paper over such issues but rather prefers to see the
issue fixed at its source. So we'd have to carry a downstream patch for
this.



-- 
Why is it that all of the instruments seeking intelligent life in the
universe are pointed away from Earth?

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