Tag Archives: backup

Restore an etc configuration file from the original maintainer version on Debian

There are events that can not be stopped, for example when you delete a file by mistake under /etc.

Debian provides an elegant way to restore files of the maintainer’s version without touching your existing configuration.

Practical scenario

Let’s say I’ve removed the file /etc/apache2/sites-available/000-default.conf, here’s the procedure to recover it:

  • find the deb package containing the file
    # dpkg -S /etc/apache2/sites-available/000-default.conf
    
  • reinstall the package with a specific option
    # apt-get install --reinstall -o Dpkg::Options::="--force-confmiss" apache2
    Reading package lists... Done
    Building dependency tree       
    Reading state information... Done
    0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 5 not upgraded.
    Need to get 86,7 kB of archives.
    After this operation, 0 B of additional disk space will be used.
    Get:1 http://archive.ubuntu.com/ubuntu/ saucy-updates/main apache2 amd64 2.4.6-2ubuntu2.1 [86,7 kB]
    Fetched 86,7 kB in 0s (264 kB/s)
    (Reading database ... 245864 files and directories currently installed.)
    Preparing to replace apache2 2.4.6-2ubuntu2.1 (using .../apache2_2.4.6-2ubuntu2.1_amd64.deb) ...
    Unpacking replacement apache2 ...
    Processing triggers for man-db ...
    Processing triggers for ufw ...
    Processing triggers for ureadahead ...
    ureadahead will be reprofiled on next reboot
    Setting up apache2 (2.4.6-2ubuntu2.1) ...
    
    Configuration file `/etc/apache2/sites-available/000-default.conf', does not exist on system.
    Installing new config file as you requested.
     * Restarting web server apache2
       ...done.
    

That’s all.

Practical scenario #2

There’s another interesting case when this procedure comes handy: if you changed a default etc file and you want to restore it. In that case you can simply delete it and use the same apt-get command:

# apt-get install --reinstall -o Dpkg::Options::="--force-confmiss" <package name>

References