[mythtv-users] NFS and remote backend

Ryan Steffes rbsteffes at gmail.com
Mon Jan 14 22:21:24 UTC 2008

> The other programs using the network may be more forgiving of timing
> issues.  The display of video without stuttering requires the information
> for the video frame to get to the frontend with enough time to be decoded
> and rendered. If the frontend is waiting on data from the network it
> will stutter.

Well that's what I mean.  I can bog down the network writing any
number of files and reading files with no stuttering, as long as it
isn't the file that's being recorded right then.

In other worse:

PVR-150 can record show A while I watch show B and it will be fine.
PVR-150 can record show A while I watch show A from NFS and it will stutter.
PVR-150 can record show A while I watch show A streamed from back end
and it will be fine.

Ditto for other tuners.  I can record several shows from both PVR-150
and my A180 and watch something and it'll be fine, unless the
something is being recorded right at that moment.  That makes me think
it's not the network specifically, but something about the network set
up, like a refresh issue.

> You can try the following to see if anything stands out as odd:
> Run some NFS tests with large file reads and writes on the NFS share
> from the 100 mega-bit frontend.
> Change your NFS block size on the client & server (restart NFS) and run
> the tests again.  (large file means many times greater than the 32K
> block size)
> Repeat the above tests with a crossover ether net cable connecting your
> server and client (at 100 mega-bit). This eliminates the D-Link
> router/switch.
> Install SAMBA, and run the tests again using the CIFS share from SAMBA.

Can give that a shot, I don't know of a particular reason to not
stream from the backend, since it seems to work better.  I just kinda
wanted to know /why/ it worked better.


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