Laughing Last

There’s an old saying from a poster about Murphy and computing:

He who laughs last usually made a backup.

PersistenceI cannot stress how important frequent backups and archives are. You don’t really need to make backups of your windows system and installed software since that can always be recreated. In fact, it’s more likely to work if completely reinstalled. I always divide my disk in to two partitions or use two disks: one with the OS and installed programs, and one with my data. Note, however, that Windoze keeps your profile under the “Documents and Settings” directory on the system partition, so you still have to grab a copy of that once in a while as well. <sigh>

When planning for the recovery of lost information, there are two things to consider:

  1. Backup: This is a copy of all your latest information. If your drive crashes, your computer is stolen, or a meteor lands on your home, you can go to the backup and restore all of your information. The best backups are off-site or they can be stolen, burned, or crushed by a large space rock right along with your primary.
  2. Archive: This is a sequence of backups going back a certain amount of time. These protect you from deleted or corrupted files that you do not notice until after you’ve made a new backup. A “backup” can be one point in an archive. It also should be stored off-site.

There are many ways to implement these and for true reliability, you should have several. For example, here’s my personal backup/archive strategy:

  • RAID: My user data is stored on a RAID5 system. This ensures that if any one drive fails, no data will be lost. I can replace that one drive and the array will automatically rebuild itself. My system is made of four 80GB drives for 240GB of usable space. If I were doing it again today, I’d use two 300GB drives in a RAID1 (“mirror”) configuration for simplicity, lower power consumption, and even greater reliability.
  • External HD: Once a week I plug in a 300GB external USB 2.0 hard drive and run a script to sync my primary to the external. In addition, instead of just deleting/replacing files on the external, my script moves them to a separate directory tree on the external. Thus, I have an archive of all previous versions of changed files on that drive. If the drive is getting full, I just delete the oldest archive. When the process is complete, the drive is hidden in a closet. The rsync program does the heavy lifting inside my script.
  • Tape Backup: About twice a year, I make a full archive of all my work on to 40GB tapes which get stored in a safe-deposit box in a bank vault. This provides my off-site backup.
  • CD-ROM/DVD-ROM: I periodically grab as many of my new files as will fit on a CD or DVD and burn them to disc. I then store this disc at an off-site location (my sister’s house). I’d store these in the bank vault, too, but safe-deposit boxes were made in the days of envelopes and very few are actually big enough to store a 5″ CD/DVD.

It’s not a perfect strategy. The biggest risk is the time interval between when files arrive and when an off-site copy is made. The external HD backup/archive has been of great benefit and I highly recommend this to anyone who wants to improve the reliability of their data and/or hates complicated backup strategies.

There are also on-line backups from various companies, but I haven’t tried this yet. If you’re willing to trust a third party with your data, this can provide a daily, off-site archive of all your important files. I’m interested in hearing comments from those who do use these services.

4 comments to Laughing Last

  • Very interesting article. Thanks for the writeup.
    I believe that you are forgetting physical separation:
    I back up all my photos to an external drive and then I take the drive to work and stash it away. The idea behind this is disaster control. If I am having a fire (god beware) at my place and my computers are physically destroyed, my photos will survive at my work place.
    Also I have my websites hosted at the eastcoast and soon I am having my backup ftp server running at home (california). This way, even if some major disaster happens, I will have my data in either of the two places.
    Yeah I know, it may seem a bit paranoid, but loosing the pictures would hurt a lot and the cost of backing up is nothing in comparison.

    good article!

  • I don’t think I’m forgetting that. I make several mention of “off-site” backups and archives. I used the example of a meteor strike instead of a fire, though I admin the latter is more likely.

  • My current backup strategy is very simple: I have 2 Seagate drives, I copy using SynToy files from one drive to the other one and I use one drive for working, the other one for backup. However reading the The DAM book, I can see that my current backup strategy has flaws…

  • An update… I’ve stopped using tape backup and CD/DVD media. They’re just too difficult to manage and so end up not being managed at all. My new computer also uses RAID1 (mirror) in order to require fewer drives and provide faster write speeds.

    I now use CrashPlan to archive all my data to a friend’s computer (and soon a second friend’s as well). This provides my off-site backup. CrashPlan is free for personal use with pay versions if you need some more advanced features. You can also purchase on-line storage from them if you don’t have friend’s with big enough drives or who keep their computers on and connected all the time.

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