After a shutdown or suspend, the machine appears to completely shutdown (all fans stop and are quiet), after a few seconds, everything is powered up again by itself.

Despite the many offered solutions here in the forum, my pc keeps on rebooting after shutdown and after suspend.

IMPORTANT UPDATE: it appears that the pc shuts down without restart when ZFS is performing a scrub. I assume this means that something is going wrong when the pc is shutting down with regards to ZFS (unmount? unshare ?). Any clues ?

• I tried adding acpi=noirq to the grub file, after that I executed
  update-grub.


• I tried adding acpi=no apm=no instead, but that caused suspend to not terminate properly and result in a reboot. Shutdown causes reboot like before.


• Tried sudo halt, sudo shutdown -h now


• Tried installing laptop-mode-tools in Ubuntu 12.10


• De-activated WOL


• I even tried to change "auto" to "on" in the "control" files for every device.


• Upgraded to Ubuntu 13.04 (I believe laptop-mode-tools are not available under 13.04?)


• Tried messing in the BIOS ACPI settings (switched everything off, with no result)

None of it seems to work, and I'm getting out of info on the forum...

Questions:

• Is there anybody that has an idea what could go wrong ?


• Could ZFS be the cause ?


• Or the fact that I have an additional pci-e network adapter ? (some WOL issue)


• I'm not too familiar with Ubuntu, how can I access/dump the logtext when the system is going to shutdown or suspend (not the arrow key, but a file) ?

Running Ubuntu 13.04 now, with ZFS (6 disks) as a NAS on a ASRock B75 Pro3-M, Intel Pentium G2020, 16 Gb RAM, additional pci-e network adapter.