From owner-freebsd-hackers@FreeBSD.ORG Fri May 8 08:25:50 2009 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E3635106564A for ; Fri, 8 May 2009 08:25:50 +0000 (UTC) (envelope-from kheuer2@gwdg.de) Received: from tmailer.gwdg.de (tmailer.gwdg.de [134.76.10.23]) by mx1.freebsd.org (Postfix) with ESMTP id A4DA88FC08 for ; Fri, 8 May 2009 08:25:50 +0000 (UTC) (envelope-from kheuer2@gwdg.de) Received: from gwdu60.gwdg.de ([134.76.8.60]) by mailer.gwdg.de with esmtps (TLSv1:AES256-SHA:256) (Exim 4.69) (envelope-from ) id 1M2LOv-0007ah-0y for freebsd-hackers@freebsd.org; Fri, 08 May 2009 10:25:49 +0200 Date: Fri, 8 May 2009 10:25:48 +0200 (CEST) From: Konrad Heuer To: freebsd-hackers@freebsd.org Message-ID: <20090508101555.J47014@gwdu60.gwdg.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Spam-Level: - X-Virus-Scanned: (clean) by exiscan+sophie Subject: How to invalidate NFS read cache? X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 08 May 2009 08:25:51 -0000 Hello, sporadically, I observe a strange but serious problem in our large NFS environment. NFS servers are Linux and OS X with StorNext/Xsan cluster filesystems, NFS clients Linux and FreeBSD. NFS client A changes a file, but nfs client B (running on FreeBSD) does still see the old version. On the NFS server itself, everything looks fine. Afaik the FreeBSD kernel invalidates the NFS read cache if file modification time on the server changed which should happen here but doesn't. Can I force FreeBSD (e.g. by sysctl setting) to read file buffers again unconditionally after vfs.nfs.access_cache_timeout seconds have passed? Best regards Konrad Heuer GWDG, Am Fassberg, 37077 Goettingen, Germany, kheuer2@gwdg.de