Comment # 7 on bug 1183727 from Franck Bui

(In reply to John Carrick Smith from comment #6)
> as it is the most frequent. I have attached the section of /var/log/messages
> from the initiation of shutdown until the next boot in file shutdownmessages
> attached.
> On this occasion the shutdown hung for 90s then completed.

Well can you use instead journalctl when providing the logs ? it's more
reliable especially when you need to inspect the log from the shutdown process.

From the logs you provided I can't see any interesting info.

So can you try to reproduce your problem with the debug logs enabled (run
`systemd-analyze set-log-level debug` before rebooting). When you managed to
reproduce the hang please provide the output of `journalctl -b -1` which should
show the log from the previous boot when the hang happened.