I have 2.1.1. Where exactly, in the directory structure (Linux server) are the backup files kept? I cannot find my backup files, but the backups report back that they performed correctly.
You can't really access files directly through the server's filesystem. If you go into the course you backed up and click on the 'Restore' link (Settings->Course administration->, you will see your course backup area, and you can download the backup file from there.
Ann is actually right, but not quite accurate, but understand that this is part of the general overhaul of Moodle security. If I have it right, the backup files are now encrypted and stored so that they can really only be accessed using the right keys, which are hidden in the database. This is just a guess, but not a wild one, and funnily enough, most of the internal security issue discussions are either hidden or carried out elsewhere, or couched in so esoteric terms that mere laymen, unfamiliar with PHP and MySQL security, would be able to follow it. It works though.. Cheers..