From owner-freebsd-current@FreeBSD.ORG Thu Aug 8 12:20:59 2013 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id C32B95FB for ; Thu, 8 Aug 2013 12:20:59 +0000 (UTC) (envelope-from rmacklem@uoguelph.ca) Received: from esa-jnhn.mail.uoguelph.ca (esa-jnhn.mail.uoguelph.ca [131.104.91.44]) by mx1.freebsd.org (Postfix) with ESMTP id 8AB692DF5 for ; Thu, 8 Aug 2013 12:20:59 +0000 (UTC) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AqIEAIeMA1KDaFve/2dsb2JhbABbFoMlUIMUuzWBMHSCJAEBBSNWGxgCAg0ZAlkGiCMMpx+RMYEojTiBBzQHgmeBJwOZC4h5hyyDNCCBLUE X-IronPort-AV: E=Sophos;i="4.89,838,1367985600"; d="scan'208";a="44060615" Received: from muskoka.cs.uoguelph.ca (HELO zcs3.mail.uoguelph.ca) ([131.104.91.222]) by esa-jnhn.mail.uoguelph.ca with ESMTP; 08 Aug 2013 08:20:58 -0400 Received: from zcs3.mail.uoguelph.ca (localhost.localdomain [127.0.0.1]) by zcs3.mail.uoguelph.ca (Postfix) with ESMTP id B1761B3EEF; Thu, 8 Aug 2013 08:20:58 -0400 (EDT) Date: Thu, 8 Aug 2013 08:20:58 -0400 (EDT) From: Rick Macklem To: Lars Eggert Message-ID: <1578548312.7148700.1375964458716.JavaMail.root@uoguelph.ca> In-Reply-To: Subject: Re: nfsd server cache flooded, try to increase nfsrc_floodlevel MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [172.17.91.203] X-Mailer: Zimbra 7.2.1_GA_2790 (ZimbraWebClient - FF3.0 (Win)/7.2.1_GA_2790) Cc: freebsd-current X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 08 Aug 2013 12:20:59 -0000 Lars Eggert wrote: > Hi, > > every few days or so, my -STABLE NFS server (v3 and v4) gets wedged > with a ton of messages about "nfsd server cache flooded, try to > increase nfsrc_floodlevel" in the log, and nfsstat shows TCPPeak at > 16385. It requires a reboot to unwedge, restarting the server does > not help. > > The clients are (mostly) six -CURRENT nfsv4 boxes that netboot from > the server and mount all drives from there. > > I googled around and saw that others have hit this issue, but I > haven't seen any resolution posted. I guess I can increase > NFSRVCACHE_FLOODLEVEL in the source, but I wonder if I wouldn't > simply hit the increase value after a little while longer... > > Lars > You can either try this patch (which dynamically adjusts nfsrc_floodlevel along with handling a variety of overhead issues for the DRC under heavy load): http://people.freebsd.org/~rmacklem/drc4.patch or just bump it up a bunch. The default value was safe for a server with 256Mbytes of ram and a default mbuf cluster limit. The only thing you might have to do along with bumping NFSRC_FLOODLEVEL up is increasing kern.ipc.mbclusters. The variant of the above patch will make it into head someday, once I merge in changes from ivoras@'s similar patch and confer with him about it. rick