Re: [gentoo-user] NFS Server Tuning

[Florian Philipp]

On Sat, 2008-01-26 at 10:29 +0000, Stroller wrote:
> On 25 Jan 2008, at 22:40, Florian Philipp wrote:
> > On Thu, 2008-01-24 at 19:19 -0600, Dan Farrell wrote:
> >
> > [...]
> >> and as the client (from `mount`):
> >>
> >> nfs:/mnt/storage on /home/media/storage type
> >> 	nfs(rw,rsize=65536,wsize=65536,soft,timeo=300,addr=192.168.1.88)
> >>
> >> /etc/fstab on the client looks like:
> >>
> >> nfs:/mnt/storage /home/media/storage    nfs
> >> 		rsize=65536,wsize=65536,rw,async,soft,timeo=300 0 0
> >>
> >>
> >> Of these options, rsize,wsize,and async are reputed to effect
> >> performance.  ...
> > [...]
> >
> > As far as I remember, rsize and wsize are negotiated between client
> > and
> > server. Those mount options just set an upper limit which is certainly
> > not what you want. I'm even wondering that those settings are accepted
> > at all! Normally, unsigned 16bit integer has a range from 0 to
> > 65535. If
> > you ask me, that's an off-by-one error just waiting to happen...
>
> This seems to suggest that 32768 is the largest figure that can be
> specified for rsize,wsize:
>    http://www.mythtv.org/wiki/index.php/
> Optimizing_Performance#NFS_servers
>
> Stroller.
>
>

Ehmm, yes. NFS-docs approve this.

From a programmer's perspective this number is still odd because it's
one more than can fit into signed 16bit int and and 32767 less than
unsigned 16bit int... maybe they had other reasons.

Well, although neither info- nor man-pages mention it, I've found an old
man-page [1] which states that these values default to 1024, therefore
setting it to 32768 seems the best choice. 

[1] http://www.trinler.de/de/linux/man.html?command=nfs