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So I can run on one machine:

dpkg --get-selections '*' > selection.txt

On another machine:

dpkg --set-selections < selection.txt

... followed by either of the following:

aptitude install
apt-get -u dselect-upgrade

... to install the packages that.

However, it appears that some information gets lost in the process, such as whether a package (say xyz) got installed automatically as dependency of another package (abc). You can see that whenever you do something like apt-get --purge remove abc. On the original machine you would be notified that package xyz was installed as dependency of abc and that you may use apt-get autoremove to get rid of it.

Now I am aware of deborphan and debfoster, but they're cumbersome to use given the (simple) task at hand.

It seems saving and restoring the selections as shown above is not sufficient to restore the subtle dependencies of installed packages.

Is there a way to back up the complete set of metadata for package management and restore it then in its entirety?

belacqua
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0xC0000022L
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  • I've often wondered the same thing I generate a big shell script with a 'sudo apt-get install' with all my packages (minus libs). Of course, I run into the same problem you're having. – Chuck R Feb 20 '12 at 18:17
  • I would guess that the best place to start looking would be to check if dpkg is in fact responsible for that information. If it isn't then maybe that is apt's job. – Huckle Feb 20 '12 at 19:03
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    If you're going the manual way, you may be interested in apt-mark for saving/restoring information about automatic vs manually installed packages – Lekensteyn Feb 24 '12 at 18:37
  • It's not in the 10.04 package repo, is it? Is this part of the Canonical repos or third-party? – 0xC0000022L Feb 24 '12 at 19:59
  • It starts with the problem that on a fresh system, only a few packages are marked as automatically installed, when - from a dependency tree point of view - it should be the other way around. – htorque Feb 27 '12 at 11:22
  • @htorque: so you're saying there is no solution to the problem as such? – 0xC0000022L Feb 27 '12 at 11:56
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    No, that's just a "for your information" comment. I'd use apt-mark (it's part of apt, so it should already be installed) to get and set the marks for the packages (see its manpage for details). – htorque Feb 27 '12 at 12:07
  • @htorque: thanks for the info then :) much appreciated. – 0xC0000022L Feb 28 '12 at 21:16

2 Answers2

38

Backup:

apt-mark showauto > pkgs_auto.lst
apt-mark showmanual > pkgs_manual.lst

Restore:

sudo apt-mark auto $(cat pkgs_auto.lst)
sudo apt-mark manual $(cat pkgs_manual.lst)
htorque
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  • Thanks, was about to ask that you or Lekensteyn write that up as an answer. – 0xC0000022L Feb 29 '12 at 17:51
  • Does these commands allow you to reinstall the programs from that list? – Svetlana Belkin Dec 30 '13 at 14:35
  • can this remove packages that are installed extra, at restoration? – n611x007 May 22 '14 at 11:56
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    Can you explain the difference between auto and manual ? Thanks. – Anto Jan 07 '15 at 16:33
  • I accidentally marked as manual a bunch of other packages... is there a way to revert? Thanks – dentex Oct 05 '16 at 10:49
  • Mate! I wish I'd known this when I wrote my backup script, now that I'm trying to restore everything! ☹ – Michael Scheper May 20 '17 at 20:35
  • And now that I'm trying to restore to my next system, I'm getting a whole buncho' errors: 'Unable to locate package', 'can not be marked as it is not installed', etc. So I suppose what was required was both dpkg --get-selection and these commands? :sigh: Maybe my next hardware transfer will go more smoothly. – Michael Scheper Oct 05 '18 at 12:15
5

The selected answer to this question is incomplete and does not (or no longer) works. The painful fix is to use a bash for-loop to parse the output *.lst files and feed them to apt install. Bad choice, though, so will not be illustrated here.

A better choice is to use apt-clone, as seen in this answer on the Unix & Linux Stackexchange. This creates a small file (around 100K or less for my system). Allegedly, it will clone the packages with little effort or pain.

So, in short, on the original machine:

apt-clone clone `uname -n`

Then, on the machine to clone to, copy the clone file and run:

apt-clone restore original-machine-name.apt-clone.tar.gz

I include this answer here since this page turned up in initial web searches, but the other answer did not. This method looks way easier.

tanius
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casualcoder
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