@Marshalleq The command "zfs get xattr" returns "on" as value, so i assume its enabled like you mean? Although i dont remember setting that.
@ich777The setting "Load ZFS Pools on Array start/stop:" in unraid-kernel-helper is set to false. I guess i should build a new kernel with it set to true, so the zfs array stops, when the unraid array does. But as i said, the reboot problems seems to only appear for me, when my system is pinned to 100% cpu-usage, otherwise i can normally reboot (atleast the times i tried, it worked)