Hi Ken,
Unfortunately the backup of the course is all we have. One of our technicians extracted it just prior to a server crash. We then had to revert to a backup of the database from 2 weeks prior when the course didn't exist. So now we need to restore the 4GB mbz file into a new course.
I read the articles on PHP zip and the 2GB limitation. To get around this I tried using the externalzip plugin which directs moodle to use the zip and unzip commands rather than using PHP. However, this has not worked either. I found an interesting line in the apache_error.log that says:
warning [/Applications/MAMP/data/moodle23/temp/backup/d12ce02b02a712a6e833cf865dd9cefc]: 4294967296 extra bytes at beginning or within zipfile (attempting to process anyway)
I then tried renaming the backup file with a .zip extension because an mbz file is essentially a zip file. When I use unarchive utility it extracts all the files with no issues. When I use terminal I get this:
wiki:~ moodle$ unzip /Users/moodle/Desktop/test/test.zip
Archive: /Users/moodle/Desktop/test/test.zip
warning [/Users/moodle/Desktop/test/test.zip]: 4294967296 extra bytes at beginning or within zipfile
(attempting to process anyway)
file #1: bad zipfile offset (local header sig): 4294967296
(attempting to re-compensate)
creating: 0/
inflating: 0/backup-moodle2-course-23-dp_history-20130415-1350.mbz
error: invalid compressed data to inflate
So the unzip utility is not working properly either. We are running unzip 6.0 which is supposed to handle large files. However, it seems many others are running into this issue as well. I thought it might be a corrupt zip file so I extracted the files with unarchive utility and then re-compressed them. However, unzip gave me the same results. Anyway, I'm going to keep trying to create a 4GB zip file that unzip extract.
The dca63bd27d4555d5af611f6c1e8f10af no longer exists. I'll report back if I figure anything out.
John