Subject: Re: NFS writes hang
To: None <>
From: Michael van Elst <>
List: tech-userlevel
Date: 05/28/2004 09:18:55 (Urban Boquist) writes:

>of) the standard things to try for nfs hangs is to decrease the
>read/write sizes. try adding something like ",-r=4096,-w=4096" to the
>options list of client side fstab.

Decreasing read/write sizes is supposed to avoid buffer overflows
on the receiver. Some systems can't even handle two back-to-back
packets and reducing further to 1024 (i.e. < 1500-X) is necessary
to create enough overhead between adjacent packets.

>Dave> Interestingly, rpcinfo -p client when done from the
>Dave> client also hangs.

Now this says there is a different problem. rpc probes do not
use large packets that are fragmented. Even with a saturated
link it is unlikely that no probe request will come through.

                                Michael van Elst
                                "A potential Snark may lurk in every tree."