Step 6: Conclusion and Final Thoughts

Hopefully you've managed to backup your machine(s). What follows are just a few notes on the topic.

If you're serious about backups, then TEST TEST TEST. Make sure that your backup and restore procedures are flawless. Backups that you can't restore are worthless.

One problem I ran into was setting my cache size too big. This can (basically) DoS your system and cause it to freeze. You're cache should always be a fraction of your RAM to be effective (mine's one-fifth), and should NEVER exceed your swap space size. 32MB is what dump's man page recommends. While this information may be outdated, having a large cachesize won't make much of a difference if you have all night to backup your system.

If you've automated your backups, make sure they're working. It would be a real nightmare for your system to crash and THEN realize that your backup crons quit working 6 months ago due to insufficient disk space. Cron jobs just automate the "complacency" process. If you do backups manually, don't become complacent and forget. Make it a routine. Don't rely on cron jobs either, because they can fail.

Backups are just copies of your files. This means that backups should be secured just as well, if not better than, your live systems. Keep your external harddrive in a secure location (like away from both water AND burglars). Run backup cronjobs as the 'operator' user. This is a limited account that exists for things such as this. Also make sure that normal users cannot run backups. If you feel you could potentially be the target of a sophisticated attack (or even if you don't), always encrypt data transfered during remote backups. Due to the amount of information, as well as regularity of backups (if you're using cronjobs), hackers can take their time in stealing your information. Encryption's easy, so use it. Make sure that normal users can't run backups to their own devices. Also, `scp` requires authentication. I HIGHLY recommend preshared public/private keys. You don't want your password to be transmitted everytime a backup is run.
Back up is good
Interesting article. Always good when people post helpful solutions. Also another method is to use rsnapshot, which uses rsync. You can do daily's, weekly's, etc and have multiple backups. And with rsync, it only copies what has changed in a file, or a new file, etc and with two seperate backups if a file is identical it only stores one copy of that file, thus saving space. A little more advanced would be backuppc, also using rsync, it also has a web interface.
I have to second the recommendation for backuppc. You can backup via tar or rsync with linux boxes. Windows boxes you have to use samba (you can try rsync, but the cygwin version is hosed). It pools files, in other words it only keeps one copy of a file, for instance if you back up the /etc directory on two different linux boxes, chances are many of the files will be the same and it only keeps one copy. I have used it for over a year now. It's so cool to browse to a web page and restore a single accidentally deleted file in seconds.
Well I got my rsnapshot working and it's been running for almost a week. So far I'm impressed. It's very quick. I didn't want to use the advanced backuppc for my situation, rsnapshot seems to work fine. I wrote about my experience on my blog and forum.<br/><br/>Blog: <a rel="nofollow" href="http://www.blog.cory.lievers.ca/index.php?/archives/25-Backing-up-computers-with-rsnapshot.html">Backing up computers with rsnapshot</a><br/><br/>Forum: <a rel="nofollow" href="http://www.forums.cory.lievers.ca/viewtopic.php?t=171">How to back up computers with rsnapshot</a><br/>
Great! Thanks for the links :)

About This Instructable


22 favorites


Bio: Software developer, Placethings co-founder, and technologist. Currently attending graduate school in the Emerging Media and Communications program at the University of Texas at Dallas.
More by Johntron: Backup your server Build your own gateway firewall
Add instructable to: