From owner-freebsd-performance@FreeBSD.ORG Tue Dec 28 14:15:15 2010 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id CD25F1065672 for ; Tue, 28 Dec 2010 14:15:15 +0000 (UTC) (envelope-from nicolas.haller@corp.nerim.fr) Received: from baneblade.noc.nerim.net (baneblade.noc.nerim.net [62.4.17.143]) by mx1.freebsd.org (Postfix) with ESMTP id 997BD8FC16 for ; Tue, 28 Dec 2010 14:15:15 +0000 (UTC) Received: by baneblade.noc.nerim.net (Postfix, from userid 1000) id 866251DBDE; Tue, 28 Dec 2010 14:59:41 +0100 (CET) Date: Tue, 28 Dec 2010 14:59:41 +0100 From: Nicolas Haller To: freebsd-performance@freebsd.org Message-ID: <20101228135940.GE2660@baneblade.noc.nerim.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-06-14) X-Mailman-Approved-At: Tue, 28 Dec 2010 14:56:31 +0000 Subject: tunning disk cache for pgsql? X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 28 Dec 2010 14:15:15 -0000 Hi all, I use a new box with 4GB RAM as a pgsql server. In pgsql, you can set the effective_cache_size to indicate the memory available to cache disk I/O. As "recommended", my box use 1300MB to shared buffers (IPC shared memory) and 2700 Mo to disk cache. If I look memory usage in top, it say: Mem: 1154M Active, 1911M Inact, 601M Wired, 112M Cache, 417M Buf, 148M Free So I think FreeBSD must be limited using memory to cache I/O disk by some sysctl variables but I don't know which ones. I'm a little bit confused with some posts I found in this ML :-/ If someone can help me, it will be great. Regards, -- Nicolas Haller