[mythtv-users] (almost) completely fresh install

[Michael T. Dean]

On 11/20/2017 04:18 AM, Marius Schrecker wrote:
> Hi,
>    My combined backend-frontend server has been retired and I am 
> starting work to replace it with a distributed system.
>
> I haven't taken the time to maintain the old (updated to 0.28) system 
> for quite a while now so despite the database being in a consistent 
> state, quite a few settings are either outdated cruft or no longer 
> working (my hd-pvr for example no longer works with mythtv and my 
> channel list is hopelessly out of date).
>
>   Because of this, I have decided to go for a completely fresh install 
> and configure, only saving my recordings from the old database.  I was 
> intending to use mythexport to save my recording metadata, but can't 
> make the cgi scripts work, so rather than spending time trying to 
> figure that out, am thinking of going for a "partial"restore to a new, 
> empty database, using mythconverg_backup.pl and mythconverg_restore.pl
> following the instructions 
> at https://www.mythtv.org/wiki/Database_Backup_and_Restore.
>
> Both the old and the new systems are running version 0.28
>
> Can anyone think of any reasons for NOT using this approach?

The primary reason  to not use a partial restore is because there's no 
benefit to doing so, and doing so is much more difficult than using your 
existing database (through a full restore) and much more prone to 
failure (there are many things you can do incorrectly that will either 
cause the partial restore to fail or will cause corruption in your 
database).  The partial restore is meant as a final resort for someone 
who, generally, has corrupted their database due to poking around inside 
it directly rather than using MythTV tools to modify MythTV data.

If you want to clear out your tuners and channel lists, just go to 
mythtv-setup and in Capture Cards, select "Delete All Capture Cards" 
(not "Delete All Capture Cards from <hostname>") and to clear out your 
channel lists, go to Video Sources and select "Delete All Video 
Sources."  At that point, your capture card/input/video sources 
configuration is completely clear--as pristine as a new database.

The only other thing that a new database would clear is your settings, 
but--on the bright side--we don't have any "Make my MythTV system 
inoperative and unrecoverable" setting.  So, by pulling over your 
settings from the old system, you get the benefit of having settings 
that were once known to meet your preferences.  If you don't like how 
the settings are configured when using your new system, you can change 
those few that you no longer want set how you had them.  If you have 
fewer systems than you used to have--meaning some of those host 
configurations are no longer required--there's no problem.  The settings 
data for that host will take up about a kB of on-disk storage and never 
be read into the running systems, so won't have any real impact on the 
system.

Basically, unless you've got a database with corruption only in 
non-recording-related tables, the partial restore only does 2 things for 
you:  1) it makes a ton of work and b) it acts as a placebo to make you 
feel like things are better.  But, IMHO, hours of work for a placebo 
effect is never worthwhile.

Mike