Time machine backups to Linux

Two other people's pages really helped me get Time Machine working to back various Macs up to my central Linux server:

http://pwntr.com/2012/03/03/easy-mac-os-x-lion-10-7-time-machine-backup-using-an-ubuntu-linux-server-11-10-12-04-lts-and-up/

http://feed42.blogspot.com/2012/06/time-machine-backups-to-afp-volume-over.html