[mythtv-users] problems with (full) database restore

[Stephen Worthington]

On Wed, 1 Jan 2014 10:44:04 +0000, you wrote:

>Having just done a total reinstall of the OS and mythbuntu, I was
>hesitantly hoping that I might get back some old recordings that were in
>another partition. Hesitantly because the old system had a number of
>problems, which were largely the reason for wanting to reinstall, and I did
>not want to reimport them through the database.
>
>First I did a backup of the (empty) new install.
>
>mythconverg_backup.pl
>
>and renamed the file to mythconverg-1299-20140101093254-reinstalled.sql.gz
>to be sure it wouldn't be erased by the rotation.
>Then I did a restore of the latest backup.
>
>mythconverg_restore.pl --filename mythconverg-1299-20131013074006.sql.gz
>ERROR: Unable to do a full restore. The database contains data.
>
>Tried again:
>
>mythconverg_restore.pl --drop_database --create_database --filename
>mythconverg-1299-20131013074006.sql.gz
>Successfully restored backup.
>
>It didn't work satisfactorily (stuck at "loading" the recordings screen
>with nothing coming up) so I decided to go back to the clean install. Happy
>that I had just taken a backup, I did a restore of the new system.

That sounds like you are running a newer version of the mythconverg
database on the new system, and it had to convert the old database to
the new format.  That can take quite some time, but if I remember
correctly, if you check the logs, you will see it telling you it is
doing that (run tail -f on mythbackend.log).  So if you had waited
long enough it probably would have started up and worked.  With my
huge database, I think it took over five minutes when I did my 0.26 to
0.27 upgrade.  It was long enough that I went away and did something
else rather than sitting there waiting for it to complete.

But it is actually recommended to run mythtv-setup first, before
allowing mythbackend or mythfrontend to run.  That is because the
database update process is done better by mythtv-setup - you can see
it doing it, and I think it asks permission.  After a database
upgrade, if you are running mythmusic and the music part of the
database needs an upgrade, that happens when you start mythfrontend,
and again there can be a little delay as it happens.

>mythconverg_restore.pl --drop_database --create_database --filename
>mythconverg-1299-20140101093254-reinstalled.sql.gz
>Successfully restored backup.
>
>Unfortunately, now the system is once again sluggish in navigating the
>menus, gets stuck for several seconds when pressing escape to exit the
>program etc etc---basically back to the bad old days. Sounds a bit like
>voodoo: clean system, all zippy; if changing the database can make it
>sluggish, why doesn't changing it back make it zippy again? What am I doing
>wrong? Is there any way to get it back to a zippy state without
>reinstalling the whole distribution once more?

I have no idea why restoring an empty database could cause problems
like this.  Whenever I have restored databases, it just worked.