Re: NFS ...

Jamie Lokier (lkd@tantalophile.demon.co.uk)
Fri, 18 Dec 1998 02:52:50 +0000


On Thu, Dec 17, 1998 at 11:29:49PM +0100, Kurt Garloff wrote:
> * Another Network at our department is sometimes not working very well. I
> have some filesystems mounted via NFS, but nothing essential. Only data
> mounted on some mountpoint dir and a symlink from my homedir.
> Now, if the network hangs, a ls in my homedir hangs in D state and never
> gives up. Sopmetimes, I am even not able to kill -9 the process. I am never
> able to umount the fs (no process is working with any of the files in the
> NFS mounted dir, BTW).

That's normal behaviour for NFS clients generally (goodness knows why).

`man 5 nfs' and `man 8 mount'.
Look at the `intr' option; it will give you the behaviour you want.

> * Performance could be better. A few hundred kB/s should be possible on a
> not to busy 10MBit network, should it? I often only saw 40kB/s, but the
> server machine was slow (486-100), too. Now with P-150, I see 100kB/s
> between two Linux systems, which is still a little low, isn't it?

Yes, that's low. I have seen similarly low figures on a 10MBit network,
and it turned out to be due to poor cabling. Adding and removing
various machines changed the timing drastically. We ditched the poor
quality coax cables and replaced them with CAT-5 UTP and hubs, and
the odd throughput problems completely disappeared.

Expect 300kB/s upwards.

> I'd really like to see Linux to be stronger in the NFS area. Hope your work
> will help to get this done. It's just sad to see Linux being a better samba
> server than NFS ...

Linux has a very good *user-space* NFS server, generally by the name
nfsd or unfsd. It has been around and working well for a long time.

The kernel server was written solely for performance reasons, as far as
I know. It appears to have loads of bugs, until recently. I don't use
it, as the user-space one is a bit more functional w.r.t. carving up
permissions and visibility in various parts of the exported tree.

-- Jamie

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