The problem comes us with the way bit torrent works. It's doing massive amounts of really small network IOs writing and reading blocks from the disk. In my case this happens across a 100 Mbps network. I don't think the Pi is handling it that well. The other side affect appears to be on the wdtvlivehub side of things. It looks like it's detecting the file changes and is always trying to recompile the media library. Side affect - the wdtvlivehub is not usable (but I'm sure fixable :) )
I've already added a powered USB disk to the Pi and the performance is much, much better. The next step is to relocate the existing torrents without upsetting transmission. To do this I'm going to setup a folder on the new external disk, move across my partially downloaded torrents, then mount this folder back to the original mount point.
To start with I'll create the new folders to match my existing structure
mkdir /media/usbdrive2/wdtvlivehubmkdir /media/usbdrive2/wdtvlivehub/temp
Next I'll copy the partially completed torrents across
mv /media/wdtvlivehub/temp/*.part /media/usbdrive2/wdtvlivehub/tempNext I'll add the following lines to my /etc/fstab:
/media/usbdrive2/wdtvlivehub /media/wdtvlivehub auto bind,gid=46,defaults 0 0To finish up I re-mount all the mount points specified by fstab
sudo mount -a