[mythtv-users] slave backend configuration questions

[Jeff]

At 08:51 AM 2/17/2004 -0800, Larry Matter wrote:
> > I was planning on NFS exporting the storage on the master so the slave
> > can read the files directly. I think I set Master Backend Override on the
> > slave to enable this. (yes?).
>
>I've been wondering if there is an advantage to doing this when the files
>reside on the backend machine (i.e., is mythtv streaming better/worse/same
>as getting the files over NFS).  I was under the impression this feature
>was designed for cases where the files are also NFS mounted to the
>backend.

It may not matter, I don't know.
My gut feeling is that NFS might be more "efficient" (lower CPU load) at 
this as
that's what its designed to do. Myth has multiple layers involved in terms 
of C++
libraries, QT sockets and whatnot (maybe I'm wrong about the myth 
implementation,
I haven't looked to see how it serves files).

>Obviously you want to NFS mount the storage for purposes of recording,
>just wasn't sure if NFS was ideal for playback (i.e. using the override
>setting).

Actually, what I really want is for the slave to record locally, if 
possible, and then
have the files move to the master during a "quiet" period if the slave is 
getting
too full. I guess there's no reason that it has to be this way, 100Mbit is 
more than
enough to support several 4Kbit-6Kbit "streams" but it seems cleaner this 
way. If
the slave starts watching live tv off a tuner card on the master backend 
and then the
master backend needs 2 cards for recording I'm going to have live TV on the 
network
going from the master->slave and the recorded show going from the 
slave->master.
I bet this works just fine but there's something about it that strikes me 
as less
than optimal.

OTOH, if the slave frontend had a preference for using its "local" tuner when
the tuner is idle, the master backend would have a preference for not using
the slave's tuner unless it had to and when the master had to, it would 
tell the
salve to record the show to its hard drive. Seems this would give you a bit 
less
network traffic. There might still be times where the slave frontend ends 
up watching
tv using a tuner on the master, but that really can't be helped.


> > The slave also has about 20GB of space available for recording. Will this
> > space ever be used? Do I configure the backend on the slave to point at
> > this space or do I point it at the NFS exported space? If the slave
> > records
> > something locally (assuming it can do this) will it ever move over to the
> > master?
> > Do I NFS export this directory from the slave to the master and enable
> > Master
> > Backend Override there as well?
>
>Personally, I would just use the 20g for the slave's ring buffer and avoid
>all this headache.


20GB seems excessive for a ring buffer, no? I don't mind leaving it empty
or I can use it for something else like Music or Videos and NFS export it 
to the
master (getting a bit convoluted but that's ok).

Unfortunately I used KnoppMyth to install this machine and it picked
the partition sizes. It doesn't seem to let you change these choices easily.
Obviously I can repartition the disk as I want and reinstall, telling 
KnoppMyth
to use the existing layout.



>Larry
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