[mythtv-users] Migration of recordings database to different / newer system

[Michael T. Dean]

  On 12/31/2010 11:51 AM, Will Dormann wrote:
> I'm in the progress of migrating from an old Mythtv 0.21 system to a
> completely different 0.24 system.  (different hardware, different
> capture device, different mythtv configuration, etc.)
>
> What is the best way to migrate the existing recording database
> information to the new system?  I've tried the steps outlined here:
> http://www.mythpvr.com/mythtv/tips/migrate-recordings.html

That page is broken--and years out of date--and Google should be slapped 
for showing it to you.

> but the problem I'm running into is going from 0.21 to 0.24.  The tables
> have changed between the versions and while I do see my recordings, just
> browsing through them gives errors in the mythfrontend log:
>
> 2010-12-31 11:20:28.870 Error preparing query: SELECT bookmarkupdate
> FROM recorded WHERE chanid    = :CHANID AND      starttime = :STARTTIME
> 2010-12-31 11:20:28.871 Driver error was [2/1054]:
> QMYSQL3: Unable to prepare statement
> Database error was:
> Unknown column 'bookmarkupdate' in 'field list'
>
> I'm sure there will be other problems with having 0.21 recording data in
> a 0.24 system.
>
> I know that if the entire database is using an old schema, mythbackend
> will update the schema when it starts up.  However, if just a few tables
> are using the old schema, it doesn't seem to trigger the database update.
>
> Is there a way to manually update the relevant tables to the new schema?
>   Or another technique for migrating recordings to a newer and different
> system?   I see the "partial restore" option here, but it mentions the
> need to reconfigure mythtv, so that doesn't seem like a great option.
> http://www.mythtv.org/wiki/Database_Backup_and_Restore#Partial_restore_of_a_backup
>
> Any hints?

You want to do a full restore of your old database to your new system ( 
http://www.mythtv.org/wiki/Database_Backup_and_Restore#Full_restore_of_a_specific_backup_file 
or 
http://www.mythtv.org/wiki/Database_Backup_and_Restore#Replacing_an_existing_database 
).  In the event that the new system has a new host name, you must then 
do 
http://www.mythtv.org/wiki/Database_Backup_and_Restore#Change_the_hostname_of_a_MythTV_frontend_or_backend 
immediately after restoring the database--and /definitely/ before 
starting any MythTV program on the new system.

There is no concept of "migrating" recordings or databases in 
MythTV--that's just a "myth" propogated by Google's leaving a bad, 
outdated (and wrong) link as #1 result for the search "migrate mythtv 
recordings".

Instead, the only thing you need to do is move your database and 
recordings (and, if you change host names on the system, change that 
host name in the database).  MythTV will automatically upgrade the 
existing database.

Mike