Subject: Re: NFS problems
To: Nathan J. Williams <>
From: Jukka Marin <>
List: current-users
Date: 07/19/2002 11:40:31
[About NFS lockups that I (and some other ppl) have been seeing]

On Mon, Jul 15, 2002 at 10:18:25AM -0400, Nathan J. Williams wrote:
> First thing to try: Crank down the NFS block size, with
> -r=4096,-w=4096 in /etc/fstab. It seems that there is an unfortunate
> interaction between our default NFS block size, network stack, and
> slower network cards.

This seems to help.

> What network cards are the various machines using?

Server: NetBSD 1.5R, Athlon 900 MHz
fxp0 at pci0 dev 15 function 0: Intel i82557 Ethernet, rev 8
fxp0: interrupting at irq 10
fxp0: Ethernet address 00:02:b3:1f:76:55, 10/100 Mb/s

Client1: NetBSD 1.6D, Athlon 900 MHz
rtk0 at pci0 dev 15 function 0: RealTek 8139 10/100BaseTX
rtk0: interrupting at irq 11
rtk0: Ethernet address 00:10:a7:06:19:14

Client2: NetBSD 1.6_beta4, P233 MHz
tlp0 at pci0 dev 10 function 0: DECchip 21041 Ethernet, pass 1.1
tlp0: interrupting at irq 10
tlp0: Ethernet address 00:e0:29:05:43:63
tlp0: 10baseT, 10baseT-FDX, 10base2

Client3: NetBSD 1.6_beta4, P150 MHz
wi0 at pcmcia0 function 0: IBM Corporation, IBM High Rate Wireless LAN PC
Card, Version 01.01
wi0: 802.11 address 00:02:2d:0d:c1:1c
wi0: using Lucent Technologies, WaveLAN/IEEE
wi0: Lucent Firmware: Station (6.4.1)

If Client1 is hooked up to a 10 Mbps hub, NFS locks up unless I use
-r=4096,-w=4096  _or_  TCP mount.  If I hook the same machine directly
to a 100 Mbps switch, NFS works with or without the options.

NFS read performance was tested with dd and a 40+ MB file and 64 kB block

host			no opts		-T		-r=4096,-w=4096
Client1/10Mbps		lockup		ok (692 kB/s)	ok (1006 kB/s)
Client1/100Mbps		ok (7933 kB/s)	ok (8906 kB/s)	ok (5471 kB/s)
Client2/10Mbps		lockup		ok (815 kB/s)	ok (848 kB/s)
Client3/11Mbps		lockup		ok (440 kB/s)	ok (342 kB/s)