Blog

I recently read an article by Tim Bray about personal data backup. While the article did not have a lot of specific about software to use, he did provide some very good guidelines to keep in mind.

In that spirit, I thought that I would share my own approach to backing up my personal data in my home environment.

To begin with, I should describe my home setup. My wife and I each have our own home offices with desktop computers. My desktop is running SuSE Linux 9.3 and my wife runs Windows XP Pro. The living room contains another Windows XP Pro machine that is our home entertainment center and contains a considerable amount (400GB) of music and video and is attached to our projector and stereo system.

We also have a "server closet" containing a variable number of PCs running with connected to a KVM switch and a single keyboard/monitor/mouse setup. In that closet there is always an old Debian Linux 3.1 machine, our routers, switches and cable modem. There is generally a couple of other computers depending on current projects.

At the moment I also have 4 computers sitting next to my desktop machine that are involved in the process of testing unattended system installs on refurbished computers for use by the BC Digital Divide.

That adds up to 10 computers in the house but only 3 of them really have "useful" data on them that requires backup considerations. These are mine and my wife's desktop machines and the media machine.

We use a combination of strategies to safeguard the software on our machines. The first is that we make a distinction between media of various types and other personal data. Media is kept on the media server and personal data is kept on our primary desktop machines. The one Windows XP primary desktop machine keeps all data to be backed up under it's "Documents and Settings" directory tree and that is the only part that is backed up. The rest of the system is considered to be easily replacable.

On the SuSE machine the /etc, /home, and /root directories are backed up.

All personal data on the two primary desktop machines are backed up to two different locations every night using unattended scripts that are much too complex to talk about in this discussion. For both machines a full backup is made as compressed archives to a Windows share on the media machine. Secondarily rsync is used to syncronize the personal data with a Debian Linux dedicated server located in California. Using rsync keeps the bandwidth usage to a few 10's of megabites per day.

As it happens, the backup archive on the media machine is about 4.2 GiB so it just fits on a single DVD-RW. Each night after the desktops have completed doing a full backup to the media machine, that backup archive is burnt to a DVD-RW.

The DVD-RW are rotated though a group of 6 disk, one for each day of the week. There is another set of 5 DVD-RWs that are additionally burnt on Mondays so that we have weekly snapshots for the last 5 weeks. On top of that we do an extra DVD-RW burn on or about the 1st of each month. This gives us monthly backups for the last 12 months. So with 23 rotated DVD-RWs we can find just about any version of any document over the last year.
So that was the personal data. What do we do with the media data? That just way too much data to use a traditional DVD rotation. Instead we break the media down into three groups: photos, audio and video. The photos are kept in DVD sized trees on the media server. Photos are kept in our personal data area until there is enough to dump them into the photo tree. When that is done, two copies of the photo data are made to DVD-RWs that backup those photos. That way we have 3 copies of the photos. Audio is treated the same way but using a seperate DVD set. We also have the CDs for most of this audio but it easier to burn the ripped audio than re-ripping it. Video is a little more complex. Most of the video is captured TV shows that we capture with Snapstreams Beyond TV. A lot of this content is just erased after viewing. Most programs are just not worth keeping. Some content, movies and a few TV series, are offloaded to DVD-Rs. They are not turned into the format that DVD players require but are just left in their Windows Media Player or DivX format that we have them in.