If you don’t have a HostName set on your computer then Open Directory backups are likely to fail using Time Machine. How did you promote to an Open Directory Master if you don’t have functional backups you may ask? Let’s not worry about that for now. Instead, let’s turn our attention to /var/backups. You see, if you enable Time Machine on an OS X Server, you’ll get a ServerBackup_OpenDirectoryMaster.sparseimage in that folder, which contains your Open Directory backups and gets picked up by our pal Time Machine. You can manually run a backup using the opendirectorybackup script at /Applications/Server.app/Contents/ServerRoot/usr/libexec/server_backup/opendirectorybackup. This could be automated, using expect to send a password, but…