Booting and poweroff

[Richard Vickery]

Frequently when booting the GUI hangs on the full F blue circle, and
when going to poweroff or reboot it hangs while shutting down until I
lose patience. At times I have left it hang over night only to wake to
see it still hanging for poweroff, so I reboot without waiting. I
never experienced this in i386, and may go  back to that side since
there were no problems like this. In the mean time, where is the file
that records what happened?

Thanks.

Richard