by Ken Task.
12 is the checksum ... the one sooooo big you did not include in posting.
Wouldn't hurt to add the wait_timeout would it?
Check moodledata/temp/backup/ for contenthash named directories.
Go into one of those.
Is there a backup.mbz file there with a moodle_backup.xml file? The larger the .mbz file, the longer it takes.
There is potential for clean up task of moodledata/temp/ done by cron/adhoc_task conflicting even though that's not supposed to happen with locks!
'SoS', Ken