If your server is on it's way to being fully dead, or your license has expired, you can still create backups via the command line. To do so, run the following command:
echo "action=backup&local%5Fpath=%2Fhome%2Fadmin%2Fadmin%5Fbackups%32&owner=admin&type=admin&value=multiple&when=now&where=local&who=all" >> /usr/local/directadmin/data/task.queue
And make sure that the dataskq is running by checking /var/log/cron. If it isn't you can run the dataskq manually to create the backups:
/usr/local/directadmin/dataskq d200
This will create all backups in /home/admin/admin_backups, assuming there is enough of a system left to do so.
The command to create a backup for just a single User is:
echo "action=backup&local%5Fpath=%2Fhome%2Fadmin%2Fadmin%5Fbackups&owner=admin&select%30=testuser&type=admin&value=multiple&when=now&where=local" >> /usr/local/directadmin/data/task.queue
where testuser is the account you're backing up, by admin.
Along the same lines, to restore a single User, the command is:
echo "action=restore&ip%5Fchoice=file&local%5Fpath=%2Fhome%2Fadmin%2Fadmin%5Fbackups&owner=admin&select%30=user%2Eadmin%2Etestuser%2Etar%2Egz&type=admin&value=multiple&when=now&where=local" >> /usr/local/directadmin/data/task.queue
where user%2Eadmin%2Etestuser%2Etar%2Egz is the name of the file being restored. Replace periods with %2E (hex value). Note that you can also use the testuser%2Etar%2Egz format as well, either will work. This restore specifes to use the IP stored in the backup file for the restore. If you want to specify the IP to restore him to (assuming his account doesn't exist yet), then you'd set ip_choice=select&ip=1.2.3.4 instead of ip_choice=file.