Config file issue

[uSlackr]

I upgraded to the latest 15.x version from the repo in Debian yesterday. Greyhole would not start. Here's the error:
Starting Greyhole ... Dec 22 01:07:59 ERROR test-config: You have no 'storage_pool_drive'
CRITICAL test-config: Config file parsing failed

It looks as though the up[grade package renamed the current config and replaced it with a generic one.
original was renamed "greyhole.conf.dpkg-old". Is this a "bug" ?

[gboudreau]

The /etc/greyhole.conf file is listed in the .deb conffiles list, meaning that dpkg will monitor both user modifications to this file, and changes in the packaged version of this file. If the user edited the file (your case), then installing a new package that contains a modified greyhole.conf file will prompt you what should be done with this file with something that will look like this:

Configuration file `/etc/greyhole.conf'
 ==> Modified (by you or by a script) since installation.
 ==> Package distributor has shipped an updated version.
   What would you like to do about it ?  Your options are:
    Y or I  : install the package maintainer's version
    N or O  : keep your currently-installed version
      D     : show the differences between the versions
      Z     : start a shell to examine the situation
 The default action is to keep your current version.
*** greyhole.conf (Y/I/N/O/D/Z) [default=N] ? 

You can read more details on dpkg handling of conffiles here : https://raphaelhertzog.com/2010/09/21/debian-conffile-configuration-file-managed-by-dpkg/

I would guess you might have answered Y/I inadvertently, or you used a dpkg/apt command to upgrade that defaulted to installing the new version over yours.