[mythtv-users] burning dvd's with two back ends...

[Paul Harrison]

On 15/06/10 23:58, stuart wrote:
> Hi all...
>
> I think I know the answer to this but I'd like to discuss it any ways.
> Just in case there is a creative solution out there.
>
> I have two back ends.  So my recordings are kept in both places.  This
> is pretty much transparent to the end user as myth front end can play
> shows from any back end.  But myth archive is a different story.  It,
> as far as I know (AFAIK), can only burn recordings which are local to
> the machine where the front end is running.
>
> So I cross mounted the recording directories to/from the two back
> ends.  A task that was, to say the least, confusing.  Still no luck. 
> Ah, I needed to get into the mythtv-setup program and tell each back
> end there were more directories to find recordings in.  Now, when I
> run myth archive I can see all the programs instead of only a few.
>
> But, alas, an unwanted side effect.  Because I told mythtv-setup about
> the cross mounted recording directories, the back end (I think) is
> taking advantage of the new space and is trying to store programs
> there!  Noooo!  Can you imagine the amount of bandwidth that I am
> chewing up between the two back ends?  Storing, transcoding,
> commercial flagging?!?!  When all is said and done some shows will
> probably have made the journey between the two back ends half a dozen
> times!
>
> It gets worse though.  For safety, I purposely have my nfs servers
> export everything as read only.  Can you guess what is actually
> happening ever since I set up my cross mounted mythtv recording
> directories?  I have ended up with blank programs of zero length.  I
> assume the back end randomly tries to use the mounted read only
> directory.  When this happens no file is created.  When I try to play
> back such a recording the front ends simply can not find it.
>
> In a perfect world myth archive would be able to pull a program from
> any back end and make the process as transparent as the mythtv front
> end player does.  Then I wouldn't have to cross mount the recording
> directories to/from each of the two back ends.
>
> But, for now, is there a way to tell mythtv archive about the cross
> mounted directories so it can find all the recordings while leaving
> the mythtv backend ignorant the cross mounts are there?
>
> -thanks
>

A partial solution would be to only mount the nfs shares when needed by
MythArchive. It does no harm to have a storage group directory that is
inaccessible for part of the time, the backend just ignores it. The
problem with that is it isn't user friendly and the BE may still try to
use it while an archive job is being processed.

A better solution as you alluded to is to have MythArchive detect a
recording isn't available locally and to stream it from the BE to the FE
that is running MythArchive. If someone is interested in adding this you
would need to modify mythburn.py to stream the recording from the BE,
there may already be something in the Python binding to do that for you,
or if you prefer c++ you could add and option to mytharchivehelper to
copy the recording over.

Paul H.