Hi,
Backups are very important for any system. Especially production machines. A good admin will backup via grandfathering along with on site via alternate storage means. Even tape is better than nothing. SMD is available still today for
Linux backup. CD/DVD are not necessarily my first choice but it's better than nothing. HDD is the convenient media but again not the reliable method. But to a alternate storage disk is again better than nothing. External drives can be treated as a 'SMD' but still reliability plays.
I backup through out my LAN. I don't need to grandfather but if I would need to then there are multiple services available today.
This link and others are available from '
Slackware-Links'. More than just SlackwareŽ links!