<html><br />On Tuesday, November 21, 2017 12:57 CET, "Michael T. Dean" <mtdean@thirdcontact.com> wrote:<br /> <blockquote type="cite" cite="5A14149A.6050903@thirdcontact.com">On 11/20/2017 04:18 AM, Marius Schrecker wrote:<br />> Hi,<br />> My combined backend-frontend server has been retired and I am<br />> starting work to replace it with a distributed system.<br />><br />> I haven't taken the time to maintain the old (updated to 0.28) system<br />> for quite a while now so despite the database being in a consistent<br />> state, quite a few settings are either outdated cruft or no longer<br />> working (my hd-pvr for example no longer works with mythtv and my<br />> channel list is hopelessly out of date).<br />><br />> Because of this, I have decided to go for a completely fresh install<br />> and configure, only saving my recordings from the old database. I was<br />> intending to use mythexport to save my recording metadata, but can't<br />> make the cgi scripts work, so rather than spending time trying to<br />> figure that out, am thinking of going for a "partial"restore to a new,<br />> empty database, using mythconverg_backup.pl and mythconverg_restore.pl<br />> following the instructions<br />> at https://www.mythtv.org/wiki/Database_Backup_and_Restore.<br />><br />> Both the old and the new systems are running version 0.28<br />><br />> Can anyone think of any reasons for NOT using this approach?<br /><br />The primary reason to not use a partial restore is because there's no<br />benefit to doing so, and doing so is much more difficult than using your<br />existing database (through a full restore) and much more prone to<br />failure (there are many things you can do incorrectly that will either<br />cause the partial restore to fail or will cause corruption in your<br />database). The partial restore is meant as a final resort for someone<br />who, generally, has corrupted their database due to poking around inside<br />it directly rather than using MythTV tools to modify MythTV data.<br /><br />If you want to clear out your tuners and channel lists, just go to<br />mythtv-setup and in Capture Cards, select "Delete All Capture Cards"<br />(not "Delete All Capture Cards from <hostname>") and to clear out your<br />channel lists, go to Video Sources and select "Delete All Video<br />Sources." At that point, your capture card/input/video sources<br />configuration is completely clear--as pristine as a new database.<br /><br />The only other thing that a new database would clear is your settings,<br />but--on the bright side--we don't have any "Make my MythTV system<br />inoperative and unrecoverable" setting. So, by pulling over your<br />settings from the old system, you get the benefit of having settings<br />that were once known to meet your preferences. If you don't like how<br />the settings are configured when using your new system, you can change<br />those few that you no longer want set how you had them. If you have<br />fewer systems than you used to have--meaning some of those host<br />configurations are no longer required--there's no problem. The settings<br />data for that host will take up about a kB of on-disk storage and never<br />be read into the running systems, so won't have any real impact on the<br />system.<br /><br />Basically, unless you've got a database with corruption only in<br />non-recording-related tables, the partial restore only does 2 things for<br />you: 1) it makes a ton of work and b) it acts as a placebo to make you<br />feel like things are better. But, IMHO, hours of work for a placebo<br />effect is never worthwhile.<br /><br />Mike<br />_______________________________________________<br />mythtv-users mailing list<br />mythtv-users@mythtv.org<br />http://lists.mythtv.org/mailman/listinfo/mythtv-users<br />http://wiki.mythtv.org/Mailing_List_etiquette<br />MythTV Forums: https://forum.mythtv.org</blockquote><br />Thanks Mike for putting that sop clearly,<br /><br />I'm beginning to see now that a partial restore is not the way to go.<br /><br /> One thing I know I have is a bunch of no-longer-used hostnames and channels and the mystery of my hd-pvr1212 not working any more in mythtv, although I can cat from the direct stream it produces. Probably because I did a half-baked restore of the old tuners last time I upgraded my system and replaced my first hd-pvr1212, which had died.<br /><br />Will probably forget the whole question now and do a full restore, followed by a ruthless delete of old settings.<br /><br />BR.<br /><br />--Marius--<br /><br /><br /> </html>