From owner-freebsd-amd64@FreeBSD.ORG Thu Sep 1 07:58:55 2005 Return-Path: X-Original-To: freebsd-amd64@freebsd.org Delivered-To: freebsd-amd64@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id BB93F16A41F for ; Thu, 1 Sep 2005 07:58:55 +0000 (GMT) (envelope-from hk@alogis.com) Received: from alogis.com (firewall2.alogis.com [62.8.223.1]) by mx1.FreeBSD.org (Postfix) with ESMTP id 02E1D43D45 for ; Thu, 1 Sep 2005 07:58:54 +0000 (GMT) (envelope-from hk@alogis.com) Received: from alogis.com (localhost [127.0.0.1]) by alogis.com (8.13.1/8.13.1) with ESMTP id j817wqCa020267; Thu, 1 Sep 2005 09:58:52 +0200 (CEST) (envelope-from hk@alogis.com) Received: (from hk@localhost) by alogis.com (8.13.1/8.13.1/Submit) id j817wpEi020266; Thu, 1 Sep 2005 09:58:51 +0200 (CEST) (envelope-from hk) Date: Thu, 1 Sep 2005 09:58:51 +0200 From: Holger Kipp To: Norberto Meijome Message-ID: <20050901075851.GA19900@intserv.int1.b.intern> References: <4316A5BC.1000405@meijome.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4316A5BC.1000405@meijome.net> User-Agent: Mutt/1.4.2.1i Cc: freebsd-amd64@freebsd.org Subject: Re: Which SCHED_ for DB server X-BeenThere: freebsd-amd64@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Porting FreeBSD to the AMD64 platform List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 01 Sep 2005 07:58:55 -0000 Hello, On Thu, Sep 01, 2005 at 04:54:52PM +1000, Norberto Meijome wrote: > I'm building a server that will run PostgreSQL with a database > containing several 10s of million records. The only things happening on > this box will be the SQL processes and other processes to parse raw data > and load into the DB. Users = a few connections via HTTP from an > intranet server (not more than 5 concurrently). > I was wondering what is the best SCHED_ to set in the kernel. > I currently have SCHED_4BSD but was wondering if _ULE would be better > for this I would not care that much about the scheduler you want to use. In worst case, recompile the kernel and look at performance / userinteraction. What looks worse (imho) is this: > 4 x SATA 150 drives, 90% of it RAID5 with gvinum. I do not know your applications, but if writing to disk is an issue: - WAL-files should be written to physically separated disks. - Write performance to RAID5 is not very good (tm). This is both with softraid and with hardware raid, although those raid controllers with 64MB or higher (+batterybackup) might increase the visible performance if only a few processes generate disk-i/o-load. - ATA is not good for production - better use SCSI. Best regards, Holger Kipp