Backups and Distro Upgrading

tl;dr; I don’t recommend using Déjà Dup to hold your data when you upgrade distros (e.g. from Ubuntu 11.04 to 11.10) without understanding the risks.

I’m the maintainer of the Déjà Dup backup tool that will be included by default in Ubuntu 11.10. So I’m generally biased in its favor. But I am also a cautious person.

My concern stems from the fact that Déjà Dup uses an opaque backup format [1]. Which means that it does not store your data in plain files that you can just copy back into place with the file manager. You’ll need to use Déjà Dup again to restore them [2]. Which is fine if Déjà Dup is working correctly, as it should.

But just from a risk management perspective, I always recommend that people try to have at least one copy of their data in “plain files” format at all times.

So if you back up with Déjà Dup, then wipe your disk to put Ubuntu 11.10 on there, you’re temporarily going down to zero “plain file” copies of your data. And if anything should go wrong with Déjà Dup, you’ll be very sad.

Here are a few recommended ways to upgrade:

  • Use the Ubuntu CD’s built-in upgrade support. It will leave your personal files alone, but upgrade the rest of the system.
  • Use the Update Manager to upgrade your machine. Again, this will leave all your personal files in place.
  • Copy your files to an external hard drive with your file manager and copy them back after install.

In my mind, a backup system’s primary use case is disaster recovery, where going down to zero “plain file” copies of your data is unintentional and an acceptable risk. Intentionally reducing yourself to zero copies seems unnecessary.

Hopefully, all this caution is overblown. I just want people to be aware of the risks.

[1] Déjà Dup uses an opaque format to support a feature set that just can’t be done with plain files:

  • Encryption
  • Compression
  • Incremental backups
  • Assuming little about the backup location (allowing cloud backups)
  • Supporting file permissions, even when backing up to locations that don’t

[2] There are technically ways to recover without going through the Déjà Dup interface. They just aren’t very user-friendly.

13 thoughts on “Backups and Distro Upgrading”

  1. So I’m playing around with deja-dup on my new 11.10 box and there doesn’t seem to be a way to control when backup’s occur? i.e. I can specify their frequency, but not when I want them to run. (say overnight when not using machine)

  2. Hi. the tool’s looking great in oneiric but I’m missing the nautilus extensions to restore previous versions or missing files. Any idea where they might have gone?

    Thanks again, great tool!

  3. I’m actually looking for help to restore my files after a distro upgarde. Wonder if you could help me. Thanks.

  4. Hi, I had used deja dup to backup my home folder before a fresh reinstal of Oneiric Ocelot. now Ubuntu One shows that my old backup exists, but Deja Dup’s restore option says no backup to restore on my fresh install. I have the same user names and passwords. The cloud shows my old backup, as does Deja-dup. What should I do?

    Thank you for your time.

  5. My problem is very similar to the above by Sup. My question has also been asked on Ubuntu Forums:-
    Deja Dup Restore fails: Error “No backups to restore”
    Using Ubuntu Oneiric, decided because of complicated sound problems to backup my Home Folder and re-install 11.10.
    Backed up to an external Phillips HDD, checked that the Full Backup files were there – they are, a Manifest file and some 1102 volumes each of 52.4MB. After re-installing Oneiric I tried to restore the backup but Deja Dup gives this error:-
    “Restore Failed
    No backups to restore”
    Where the blazes do I go from here? Can someone help me please!
    Acer Aspire 5735, 4GB RAM, 250GB HDD.

    ..and as Question #188112 on Launchpad. So far I haven’t had any helpful reply and am still stuck.

  6. Is it advantageous to use a strong encryption password vs a weak one? i.e. a weak one would be easy to remember but a strong one would need to be written down (and not lost!). Would a weak password be more susceptible to cracking? I think I know the answers to these but I wanted to get your opinion. Also are punctuation marks ok in passwords?

  7. This is a great point, Micheal. I’m using Deja Dup for the first time right now. Once I test a full backup and restore, I’ll be pretty confident in using it for regular backups. I hadn’t thought about the distro upgrade issue, and it’s a good one.

    Thanks for making backups in Ubuntu dead simple, by the way. I’ve been saying I need to do backups for a while, and this tool actually got me to do it :-).

  8. Today, Déjà dup saved me several months of work that I lost due to a hardware crash.
    Yet, I had made a backup via a shell script, but the backup was buggy.
    I then thought to attempt recovery with Déjà Dup which (2 year ago) was configured to make a backup per week (since, Déjà Dup do his job so well that I had forgotten it).

    It worked! Big thanks 😉

  9. It’s not that Deja Dup / duplicity is the worst backup software ever. It’s that Canonical made Deja Dup automatically start after Ubuntu was installed and automatically prompt the user to run it. Maintainers of the software send out warnings in some remote blog while the Deja Dup application does not warn about issues. If someone were to take this to court how would a “no warranty…” disclaimer hold up when the manufacturer took so many steps to actively encourage people to use the software combined with the manufacturer not presenting warnings about issues?

    Searching the web will reveal that many people have had to resort to emergency recovery procedures. How many fewer would have had to suffer through all of that if this half-baked backup program had not been promoted so much?

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