[mythtv-users] New server problems

[Michael T. Dean]

On 10/24/2014 12:20 PM, Joseph Fry wrote:
>>>>>> Further reading of the mythconverg_restore.pl material in --help
>>>>>> --help convinced me that a partial restore was what I really wanted.
>>>>> No, that's not what you want.  There is never a reason to do a partial
>>>>> restore of the database unless you have a corrupt schema and/or corrupt
>>>>> data in certain tables (the ones that aren't included in the partial
>>>>> restore).
>>>> ***
>>>> It may not be what I want but the description of the option
>>>> --partial_restore clearly states that it is required when setting up MythTV
>>>> on new hardware. Is that not so?
>>> Well, it shouldn't.  Long ago, that was the approach that was used.
>>> We've since found out that it's completely useless.
>> Actually, useless isn't the proper word.  It's beyond useless--it's
>> downright dangerous.  It makes it extremely likely for misconfiguration to
>> occur (since most users don't necessarily know all the configuration
>> options they've set over the years of using MythTV, and those that do may
>> not recognize where/how to set them with the changes to the configuration
>> system that have occurred since they originally specified them).  And at
>> the end--though people once thought there was benefit--there's absolutely
>> no benefit to the process other than saving approximately 4-8kB of HDD
>> space (not RAM, just space on the hard drive) in the MySQL data files per
>> host that was once used and is no longer used.  And, if all that's changing
>> is the name of the hosts (and not the number of hosts) in use, then the
>> mythconverg_restore.pl --change_hostname option can be used against a
>> full restore to make it so no space is saved.
>>
>> A much better process for new hardware setup is to do a full restore,
>> then--if necessary--mythconverg_restore.pl --change_hostname (for all
>> hosts whose name you're changing), then go into mythtv-setup and "Delete
>> all capture cards" (not "Delete all capture cards on<hostname>") and
>> "Delete all video sources", then reconfigure just the TV capture portions.
>>
>> I'll try to make some time to push a fix that removes the "new hardware"
>> stuff from the script documentation.
>
> Dangerous is an awfully strong word. A partial restore is appropriate in
> some circumstances, the user just needs to understand when.  If the
> objective is to preserve nothing but your existing recordings, rules, and
> history... it's a great solution.  Only appropriate in a few situations
> though, for example:
>
> a) you want to start over on a new build and clean out years of tweaks you
> may have made, knowing that you may have to remake some of them.

That's the point.  There's no benefit to this.  There is nothing you've 
set that you can't unset--almost all settings are just user options 
based on user preference and need not be configured any specific way to 
get a working system, so clearing them out/setting them to default 
doesn't accomplish anything other than changing the way MythTV works 
from the way you prefer to the way "some else" prefers.  And, more 
importantly, there's almost no situation at all where something you had 
once set will need to be unset, with the small exception being TV 
capture settings, but...

> b) your entire environment changed such that starting over is easier than
> cleaning up the old, for example you bought all new backend&  frontend
> hardware and are moving from SD to HD sources (something I actually did
> once)

Delete all capture cards deletes *all* of the TV capture settings.  
Delete all video sources deletes all of the channel configuration (i.e. 
if you're moving to a new TV market or changing cable/satellite/TV 
signal providers).  New backend and frontend hardware (the non-capture 
portions) have no special settings compared to previous hardware--as a 
matter of fact, other than capture card/input/disecq settings, there 
really aren't any hardware-specific settings in all of MythTV.  The 
closest to a hardware-related non-capture setting is your video decoder 
choice in Playback Profiles, but changing the Playback Profile Group is 
a simple change--and one that would almost definitely need to be made 
even after setting it back to defaults***

> c) You are building out a box for a friend/family member and are
> pre-loading it with content from your box.
Well, since the only content that you could possibly be sharing--since 
you wouldn't share any of the copyrighted content that you time-shifted 
by recording (allowing *you* to watch the broadcasted show at a later 
time)--is Video Library content, putting it on a new system is simply a 
matter of putting it in place in the Videos Storage Group.  And even if 
you do illegally share those copyrighted shows (and please don't say so 
if you do since stealing is not what MythTV is about and we don't allow 
discussion of it on list), you don't want your recording history to 
prevent your friend/family member from recording shows they want.

The *only* situation where --partial_restore is the proper answer is 
when you have a known-corrupt schema and/or known-corrupt data (in the 
non-recordings/non-rules/non-recording-history parts of MythTV) and you 
want to fix it/get back to a proper/working schema.  And if you have 
known-corrupt data in some of the recordings-related parts of MythTV, 
even a partial restore may not work--you may need to start over from 
scratch.

Mike


*** And even if you've changed the example Playback Profile Groups, you 
can reset them to defaults as described here: 
https://www.mythtv.org/wiki/Playback_profiles#Default_profile_groups .  
And if you want to reset your key bindings, just choose "Reset All Keys 
to Defaults" in the mythfrontend Utilities/Setup|Edit Keys section, and 
if you want to get rid of all Storage Groups, run mythtv-setup on the 
master host and select DELETE ("D") on each Storage Group listed and 
confirm the delete when prompted, and ...  The only settings we don't 
have a "reset to default" for (yet) are the user-preference settings, 
and rather than resetting those to defaults (someone else's preference) 
and trying to then find and set the ones for which you had a different 
preference, it makes more sense to just go through with your current 
preferences and see if there's anything you'd like to change.