[mythtv-users] Question re: multiple backends & where recordings are stored

[Robin Gilks]

> I have a couple of questions about running multiple Backends.  If anyone
> could set me straight, that'd be great.
>
> I currently plan on having one master backend sitting in my wiring closet
> in
> the basement.  It has two HD cards for OTA.  It's a beefy machine with
> dual
> CPUs, plenty of RAM & storage.
>
> In addition to the backend, I plan on having 2 other machines.  1.) a
> combo
> backend/frontend (PVR-150 connected to DirecTV), and 2.) basic frontend.
>
> With this in mind, my questions are these:
>
> 1.) When the combo backend/frontend records a show, where is that stored?
> 2.) When the frontend-only wants to watch the show recorded in question
> #1,
> does it stream the show from the master backend, or from the combo
> frontend/backend?  (I assume the show is stored on the combo box, and
> therefore streamed from the combo box).
>
> Unfortunately, the combo frontend/backend isn't a beefy machine and I have
> concerns if it is going to be doing 3 things at once (streaming between
> frontend and master backend, playback, and recording).
>
> 3.) If I take the combo machine's /myth dir and NFS mount it to the master
> backend, does that change the answer to question #2?  Would anything else
> change the answer to #2 (short of moving the PVR-150 to the master
> backend)?
>

Although there are patches about to split storage across multiple
backends, the preferred method is to NFS (or CIFS/SMB) mount all backends
to a common path. Say you have the storage physically on the master
backend in the basement in say /mnt/store. Set the mountpoint on the 2
slave backends so that they mount that volume to a mountpoint that is the
same (i.e. /mnt/store on each one). That way, when it comes to play back a
recording each frontend will be able to just pick it up from the shared
disk space without the backend that recorded it having to stream it (or
even being powered up if its a slave).

This approach also makes it easier to secure all your eggs (even if they
are all in the one basket) by running a raid array on the master.

-- 
Robin Gilks