[mythtv-users] NFS and remote backend

Charles Mason charlie.mas at gmail.com
Sun Jan 6 18:20:46 UTC 2008

On 1/6/08, Brian <listmail at miatar.org> wrote:
> jongi wrote:
> You can try by increasing the buffer size by adding rsize=$kb,wsize=$kb
> in the options section where $kb is the amount of buffer in kilobytes.
> IIRC, Linux kernels over 2.4 default to an 8k buffer. Maybe try 32k
> ($kb=32768)?
> I've found that SCP, NFS and Samba all operate at the same speed (pretty
> much). I'm not sure how FTP speed places in that group. Maybe try a test
> using SCP to isolate if it's a network problem or NFS problem?

I have just finshed setting up my Myth TV system, bascily the storage
is on an array of drives using ZFS RaidZ running on FreeBSD 7.0 . This
is shared via NFS over a 100 meg lan to the main backend / frontend
running mythbuntu. That appears to work really well, its impossible to
tell its not stored locally.

This lan is is joined to the rest of the network via a wirless
adapter. This is to enable me to whatch the recordings and use the
file server on my windows machines up stairs. These are all shared via
samaba from the file server.

I am able to stream upstairs via Samba, recordings from the file
server perfectly, these are the raw mpg files recorded from Freeview
(uk free to air DVB-T). However if two machines on the up stairs
network try and stream a recording at the same time playback breaks
horribly on both machines, as they are starved of bandwidth, from the
wireless linking the two networks. I have bnechmarked the wireless
link at about 2.5 megabytes per sec. Considering a BBC 1 show averages
15 megabits per sec, that would allow enough room to stream only one
show at a time, which is what I am experencing.

As I understand it normally NFS is slightly quicker than Samba at
sharing files between two unix/linux machines, although theres not a
lot in it. To be honest I havn't seen much difference, but I think NFS
is a better solution if you don't need to share with windows machines.

One thing you might want to look at is using autofs to auto mount the
networked storage when its accessed. This lets you more seemlessley
recover from restarts of the file server.

Hope that helps.

Charlie M

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