From owner-freebsd-performance@FreeBSD.ORG Wed Sep 3 11:02:44 2003 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 8AA0C16A4BF; Wed, 3 Sep 2003 11:02:44 -0700 (PDT) Received: from Chow.corp.media.net (rottie.media.net [66.113.65.4]) by mx1.FreeBSD.org (Postfix) with ESMTP id C247543FCB; Wed, 3 Sep 2003 11:02:43 -0700 (PDT) (envelope-from max.clark@media.net) Received: from MCLARK (76.0.6.10.IN-ADDR.ARPA [10.6.0.76]) by Chow.corp.media.net (Netscape Messaging Server 4.15) with SMTP id HKNGKM00.J4F; Wed, 3 Sep 2003 10:57:58 -0700 From: "Max Clark" To: "Petri Helenius" Date: Wed, 3 Sep 2003 11:08:28 -0700 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2911.0) Importance: Normal In-Reply-To: <3F56210E.7010206@he.iki.fi> X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 cc: freebsd-hackers@freebsd.org cc: freebsd-performance@freebsd.org Subject: RE: 20TB Storage System (fsck????) X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 03 Sep 2003 18:02:44 -0000 Ohh, that's an interesting snag. I was under the impression that 5.x w/ PAE could address more than 4GB of Ram. - The PAE support allows FreeBSD machines to make use of more than 4 gigabytes of RAM. This functionality was originally written by Jake Burkholder under contract with DARPA and Network Associates Laboratories. Additional changes for individual device drivers will follow in the coming weeks. If fsck requires 700K for each 1GB of Disk, we are talking about 7GB of Ram for 10TB of disk. Is this correct? Will PAE not function correctly to give me 8GB of Ram? To check 10TB of disk? Is there anyway to bypass this requirement and split fsck into smaller chunks? Being able to fsck my disk is kinda important. I have zero experience with either itanium or opteron. What is the current status of support for these processors in FreeBSD? What would the preferred CPU be? Will there be PCI cards that I would not be able to use in either of these systems? Thanks, -Max -----Original Message----- From: Petri Helenius [mailto:pete@he.iki.fi] Sent: Wednesday, September 03, 2003 10:13 AM To: Max Clark Cc: Dan Nelson; freebsd-performance@freebsd.org Subject: Re: 20TB Storage System Max Clark wrote: >- What exactly is the fsck problem? What do I do about it? > > > fsck requires approximately 700k memory for each gigabyte of disk space. I´m unfortunately not familiar enough with the issue how this splits out for blocks and inodes (for example if having only a million inodes on a 10TB fs would make it tolerable) but taking the figure presented earlier, you would need 7GB of memory for checking a 10TB filesystem. Having that kind of memory for a single process neccessiates a 64bit system, like sparc64, alpha, itanic or opteron. Pete