From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id q1H2nsHf044630 for ; Thu, 16 Feb 2012 20:49:55 -0600 Received: from ipmail07.adl2.internode.on.net (ipmail07.adl2.internode.on.net [150.101.137.131]) by cuda.sgi.com with ESMTP id OZjLAtl2YyrP3shH for ; Thu, 16 Feb 2012 18:49:53 -0800 (PST) Date: Fri, 17 Feb 2012 13:49:41 +1100 From: Dave Chinner Subject: Re: XFS memory recomendation? Message-ID: <20120217024941.GH14132@dastard> References: <2BF070A7A2375D46BA1B6087F8D5DCB68BEA721CA3@seldmbx01.corpusers.net> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <2BF070A7A2375D46BA1B6087F8D5DCB68BEA721CA3@seldmbx01.corpusers.net> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: "Assarsson, Emil" Cc: "xfs@oss.sgi.com" On Thu, Feb 16, 2012 at 12:50:57PM +0100, Assarsson, Emil wrote: > Hi, > > Are there any recommendations about how much memory I need based > on the size of the file system and/or amount of files? For > example: how much memory would be optimal for a 20TB file system > with 3000000 files? /me shrugs > I guess it depends on the usage pattern? Totally. > Is there any way to make sure that the file allocation table stays in the memory? What's a "file allocation table"? XFS doesn't have one. :) XFS does have a sophisticated metadata cache and reclaim scheme that keeps frequently referenced metadata hot in cache, but you as a user have very little control over that because the cache size is effectively controlled by memory pressure. i.e. it's size is completely workload dependent..... Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs