[SATLUG] NFS Mounts

Richard Maynard richard.maynard at gmail.com
Fri Dec 21 17:33:27 CST 2007


>
>
> Could the intr option serve as a workaround for the scenarios you gave
> when using hard mounts? I think I know the answer (no), but would like
> to confirm.
>
>

The intr options allows you to interupt the request, which requires
intervention unless the application can issue NFS interupts, which most
don't on their own.


>
> The server is running CentOS 5.1 and the client I'm using is Ubuntu
> 7.10. I wonder if the switch between the two might be flaky or possibly
> one of the NICs.


To start the troubleshooting process, I'd suggest swiching to TCP for your
NFS mounts, to do this simply add proto=tcp to your mount. If this fixes
your problem, it's likely network related, and quite honestly in a home
network I don't think it's worth switching back to UDP from TCP if TCP
solves it for you. The only time it would matter is if you were trying to
get the efficiency gains of using UDP instead of the heaver TCP
conversations.


>
> Any suggestions on how I might track down the issue? Considering this is
> my home network, I don't think pouring over tcpdump or wireshark
> captures is going to be worth my time except for the experience I could
> possibly use down the road.
>
>

Well, what I said about switching to TCP, and take a look at netstat -in,  I
think that will show you interface errors, though I'm not 100% sure as I'm
not at a linux box right now, I'm more well versed in Solaris and the
options of it's included tools. Interface errors are an obvious sign of
network problems. Just try running a long term ping, and see if you start
dropping packets, that'll also help to determine if there is a network
issue.

With a gig network in the home, most of your applications won't be pushing
even close to wire speeds, so it's possible when you're doing manipulation
of the large files over NFS it's slamming your router with network traffic.
My el-cheapo DLink doesn't have the CPU to deal with the kind of network
traffic they claim it can support, so if the other options don't show
anything you could try and force your connection to 100mbit and see if the
problems persist.

-- 
Richard Maynard


More information about the SATLUG mailing list