[mythtv-users] Questions about master/slave BE

[Peter Carlsson]

On Wed, Jun 09, 2010 at 12:00:02PM +0000, Nick Morrott wrote:
> On 8 June 2010 12:22, Peter Carlsson <maillist.peter at home.se> wrote:
> > Hello!
> >
> > I currently have a dedicated BE/FE that I power on/off according to
> > scheduled recordings. I also have a general server for file sharing,
> > web applications, backup and such that is already on 24/7.
> >
> > I would like this general server to also become the master MythTV BE
> > and turn my current BE/FE into a slave BE and FE.
> >
> > This way the mythweb will be available 24/7 and it would also be
> > possible to schedule new recordings whenever I want.
> >
> > Are there any pros/cons with this setup?
> 
> Other than ensuring the general server you are proposing to use as
> your master backend has enough "spare capacity" (CPU/memory/HDD) to
> function in its new role, not really. You should make good saving on
> power as your fileserver is already on 24/7.
> 
> If there is a chance you might want to add more capture cards in the
> future into the master backend, you might want to think about that. Of
> course, if you are also running a slave backend/frontend, you could
> add the additional cards into that - it really depends on how many
> recordings you make.

Initially, I will keep the capture cards and storage on the slave BE.
This machine is connected to my home theatre and is the only place
I watch the recordings.

But as you mention, it's worth considering what I want in the future.

> > I have installed the same version of MythTV BE on both machines.
> >
> > Would I have to do something else than:
> > 1. Export database from current BE/FE
> > 2. Import database on new master BE
> > 3. Set new master BE to listen on its 192.168.1.x port
> > 4. Point the current BE/FE to the new master BE 192.168.1.x port
> 
> See http://www.mythtv.org/wiki/Database_Backup_and_Restore#Change_the_hostname_of_a_MythTV_frontend_or_backend
> 
> You will need to delete and reconfigure your capture cards in the new
> machine, as these are stored against the hostname of the machine they
> are in. Frontend settings are also stored against a hostname or unique
> identifier, so these will be lost unless you update the hostname they
> are associated with.

I don't intent to rename my machines. The old BE/FE is called 'htpc'
and the new master BE is called 'server'. I was in a very creative
mode when I named them as you can see...

Can I still keep it that way or should I rename them in the database
to their IP addresses (192.168.1.x)?
 
> > After this migration, will the slave BE sync to the new master BE on
> > every power on and then periodically?
> 
> Not quite sure what you are asking. A slave backend does not run a
> local MythTV database, or sync recording files with the master backend
> - it acquires all settings from the database running (typically) on
> the master backend. You could store recordings made on the slave BE on
> the master backend/fileserver by exporting shares - this way
> recordings made on the slave backend will still be watchable when it
> is turned off - it really depends on the volume of recordings your
> slave machine will make and whether the storage subsystem on the
> fileserver will handle this additional load.

My misunderstanding. But is it true that since the old BE/FE will have
capture cards it has to be a slave BE or otherwise, without capture
cards, it could just be a FE?

Best regards,
Peter Carlsson