From owner-freebsd-net@FreeBSD.ORG Fri May 3 23:41:47 2013 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id 76AA0658 for ; Fri, 3 May 2013 23:41:47 +0000 (UTC) (envelope-from feenberg@nber.org) Received: from mail2.nber.org (mail2.nber.org [66.251.72.79]) by mx1.freebsd.org (Postfix) with ESMTP id 3BD871BB6 for ; Fri, 3 May 2013 23:41:46 +0000 (UTC) Received: from nber6 (nber6.nber.org [66.251.72.76]) by mail2.nber.org (8.14.4/8.14.4) with ESMTP id r43Nfiri073210; Fri, 3 May 2013 19:41:44 -0400 (EDT) (envelope-from feenberg@nber.org) Date: Fri, 3 May 2013 19:27:23 -0400 (EDT) From: Daniel Feenberg X-X-Sender: feenberg@nber6 To: freebsd-net@freebsd.org Subject: Restarting exports disturbs clients Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Anti-Virus: Kaspersky Anti-Virus for Linux Mail Server 5.6.39/RELEASE, bases: 20130503 #9879565, check: 20130503 clean X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 03 May 2013 23:41:47 -0000 When we change the exportfs file on our FreeBSD 9.1 fileserver and signal mountd to reread the file: kill -HUP `cat /var/run/mountd.pid` it kills the jobs on clients that have files open on the fileserver. They terminate with an I/O error. The same thing happens if NFS is restarted. This is pretty inconvenient for users (and us). Is there a way around this? We have noticed that a Linux fileserver can restart nfs without distrubing clients (other than a short pause). The Linux restart doesn't restart the locking mechanism - is that the difference? We could do without locks, even without NFSv4, for that matter, if it would let us change exports without disturbing users. Perhaps there there is an NFS shutdown procedure that we should be using? Daniel Feenberg NBER