[mythtv-users] Migrating to new master backend

[Michael T. Dean]

  On 10/10/2010 05:12 AM, Jan Ceuleers wrote:
> Recently the motherboard of my main server went bad and I replaced it 
> with something I had lying around. This server hosts most of my 
> applications including MythTV's master backend (but not only that). It 
> also contains most of my storage.
>
> The temporary motherboard is not fully reliable, as it seems to crash 
> under heavy simultaneous disk and network load.
>
> So I got a replacement system and want to migrate services across to 
> it. I'd like to understand what my constraints are:
>
> - Is it possible to migrate the master backend to another host (i.e. 
> one that has another IP address and/or hostname), or do either of 
> these parameters absolutely have to remain the same?

Restore the backed-up database ( 
http://www.mythtv.org/wiki/Database_Backup_and_Restore and 
http://www.mythtv.org/wiki/Database_Backup_and_Restore#Full_restore_of_a_specific_backup_file 
) to the MySQL server on the new host.  Then--before running any MythTV 
applications at all--do

http://www.mythtv.org/wiki/Database_Backup_and_Restore#Change_the_hostname_of_a_MythTV_frontend_or_backend

to change the hostname of the old backend to the hostname of the new 
backend.  Then, start up mythtv-setup and change the master backend IP 
address in general settings.

> - I'd like to start over, distribution-wise, on the new hardware, 
> because (1) the current system is suffering a bit from tinker-rot, and 
> (2) the new hardware is 64-bit capable which the current system isn't. 
> So this is going to take a while and I'd like to get the new system up 
> before taking the old-one down. I'm quite happy to do the thinking on 
> this-one; but I'd be grateful if anyone could give me a head start.

You won't be able to merge the database from the temporary system with 
the database you set up as you're testing the new hardware, but you 
could just drop and replace the database on the new hardware once you've 
proven to yourself it's ready.  Or, if you want to try to move only the 
recordings, recording history, and recording rules from the old system, 
you could use 
http://www.mythtv.org/wiki/Database_Backup_and_Restore#Partial_restore_of_a_backup 
(but note that the partial restore leaves a lot of opportunity for 
mistakes--meaning it will fail if your system doesn't exactly meet the 
prerequisite conditions--so make sure you back up both databases before 
going down that path).

That said, if you do record a few shows with the new system, you could 
throw them into MythVideo to watch them (but trying to record anything 
on the new system before it gets the old database is likely to cause 
duplicate entries that will cause failures for a partial restore).  So, 
really, the best approach is to just move the entire database over from 
the old system.

Mike