Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1WpoKT-0003Xj-8B for pgsql-performance@arkaria.postgresql.org; Thu, 29 May 2014 00:36:21 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.80) (envelope-from ) id 1WpoKS-00084h-2x for pgsql-performance@arkaria.postgresql.org; Thu, 29 May 2014 00:36:20 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1WpoKP-00084Y-Tf for pgsql-performance@postgresql.org; Thu, 29 May 2014 00:36:17 +0000 Received: from smtp.01.com ([192.254.77.197]) by magus.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1WpoKG-0004we-Kx for pgsql-performance@postgresql.org; Thu, 29 May 2014 00:36:16 +0000 Received: from localhost (localhost [127.0.0.1]) by smtp-out-1.01.com (Postfix) with ESMTP id 8F1F1A06D9 for ; Wed, 28 May 2014 19:36:06 -0500 (CDT) X-Virus-Scanned: amavisd-new at smtp-out-1.01.com Received: from smtp.01.com ([127.0.0.1]) by localhost (smtp-out-1.01.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id NqhwQzuy8AlR for ; Wed, 28 May 2014 19:36:06 -0500 (CDT) Received: from smtp.01.com (localhost [127.0.0.1]) by smtp-out-1.01.com (Postfix) with ESMTP id 646EBA06DC for ; Wed, 28 May 2014 19:36:06 -0500 (CDT) Received: from localhost (localhost [127.0.0.1]) by smtp-out-1.01.com (Postfix) with ESMTP id 4B0E6A06DA for ; Wed, 28 May 2014 19:36:06 -0500 (CDT) X-Virus-Scanned: amavisd-new at smtp-out-1.01.com Received: from smtp.01.com ([127.0.0.1]) by localhost (smtp-out-1.01.com [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id 75zdRZiYr_G4 for ; Wed, 28 May 2014 19:36:05 -0500 (CDT) Received: from [192.168.47.104] (70-36-139-100.dsl.dynamic.sonic.net [70.36.139.100]) by smtp-out-1.01.com (Postfix) with ESMTPSA id A6228A06D9 for ; Wed, 28 May 2014 19:36:05 -0500 (CDT) Message-ID: <538680F4.1070501@agliodbs.com> Date: Wed, 28 May 2014 17:36:04 -0700 From: Josh Berkus Organization: PostgreSQL Experts Inc. User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: pgsql-performance@postgresql.org Subject: Re: NFS, file system cache and shared_buffers References: <53848490.6060001@vmware.com> <20140527144013.GL2556@tamriel.snowman.net> In-Reply-To: X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Pg-Spam-Score: -1.9 (-) List-Archive: List-Help: List-ID: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: X-Mailing-List: pgsql-performance Precedence: bulk Sender: pgsql-performance-owner@postgresql.org >> Why would they implement their own client? Did they have to do something special in their client to >> make it safe? > > I think it is mostly a performance issue. Each backend mounts its own copy > of the data files it needs. I personally would never put PostgreSQL on an NFS share on Linux. Unless things have changed radically in the last couple years, Linux's NFS code is flaky and unreliable, including flat-out lying about whether stuff has been sent and received or not. This is why NetApp's NFS servers came with their own, proprietary, Linux kernel module. NFS on Solaris/Illumos is a different story. Not sure about FreeBSD. -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance