arcam rDac & nfs mounting

It took some doing to get my Arcam rDAC to play music from my NAS via NFS, and thought I’d share in case it helps anyone else.

There is a bug in the UI, where it does not honor/apply the rsize & wsize NFS mount options. It is easy enough to fix:

  • Fire up your favorite editor (vi, right?) and edit /var/www/inc/player_lib.php
  • Search for the nfs mount command and replace it with this:
    else {
    // nfs mount
    $mountstr = “mount -t nfs -o “.“rsize=”.$mp[0][‘rsize’].”,wsize=”.$mp[0][‘wsize’].",".$mp[0][‘options’]." “”.$mp[0][‘address’].":/".$mp[0][‘remotedir’]."" “/mnt/NAS/”.$mp[0][‘name’].""";
    }

I added “dwc_otg.fiq_split_enable=0” to the end of the file /boot/cmdline.txt. Since I did a few things for the DAC to work, this may or may not be required.

I used bcmstat.sh to monitor the system during playback. I noticed that when the audio would crackle, gurgle, hiccup was due to large chunks of data being read. To resolve this, I tweaked the rsize/wsize values for the NFS advanced settings. (This is also why I hacked up the above php. The default NFS mount rsize was something like 54K, vs. 4K which works much better.)

Hope this helps someone!
Elliot