One of the heaviest processes in anything Moodle is quiz. What, if anything, do apache error logs say upon the failure of backing up your course manually?
No questions.xml ... is not good ... think Moodle generates .xml files first to use as road maps for each part/piece of the backup process. Are we running out of memory? The default PHP limit of 128Meg for a 2.9.x Moodle is too low. When investigating how 2.9 does backups, had to increase not only the memory allowed to use but also, the time for a script to run - and that was on a small 1 quiz course.
Can see those values in Server's PHP Info.
If those look acceptable, then ...
Ok, know what I'm about to suggest is a pain ... but if no question.xml was present ...
2.9 has that 'easy skip to end' button so users don't have to step through the various backup screens. Step through the screens ...
Here comes the pain ... create a no user backup and exclude all quizzes but do include all other activities. Name the backup with a -nq (no quiz) in it's name - no users selected will auto insert a 'nu' at the end of the backup file name. Did it finish?
Then create another backup this time selecting no activities but the first half of the quizzes. Filename: backupblah-qz-1-10
Did that one finish?
Then create another backup this time selecting no activities including the first half of the quizzes. Filename: backup-blah-qz-11-20.
Did that one finish?
There's something else to try ... command line backup of the course ...
cd moodlecode/admin/cli/
php backup.php --courseid=[courseIDnumber] --destination=/pathto/some/large/space/you/can/access/
That takes apache out of the loop ... just php and mysql then.
'spirit of sharing', Ken
