From mboxrd@z Thu Jan 1 00:00:00 1970 From: Frank van Maarseveen Subject: some thoughts about configuring a server Date: Tue, 17 Jul 2007 14:54:28 +0200 Message-ID: <20070717125428.GA17627@janus> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: Linux NFS mailing list Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list2-new.sourceforge.net with esmtp (Exim 4.43) id 1IAmZR-0001jR-9d for nfs@lists.sourceforge.net; Tue, 17 Jul 2007 05:54:29 -0700 Received: from frankvm.xs4all.nl ([80.126.170.174] helo=janus.localdomain) by mail.sourceforge.net with esmtp (Exim 4.44) id 1IAmZT-0000VI-QP for nfs@lists.sourceforge.net; Tue, 17 Jul 2007 05:54:33 -0700 List-Id: "Discussion of NFS under Linux development, interoperability, and testing." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nfs-bounces@lists.sourceforge.net Errors-To: nfs-bounces@lists.sourceforge.net My little theory is that (NFSv3) servers should primarily cache metadata (inodes, dentries, block bitmaps) and clients should cache data and associated metadata (as far as possible) for a specific working set. why? 1) because a server generally cannot cache all the data. 2) The subjective (perceived) performance for interactive use at the client is largely determined by responsiveness e.g. how much time it takes before "ls -l" starts printing. Clients must see each others metadata updates very soon and that goes through the server. Caching metadata there will reduce disk seeks. Assuming the above, the amount of server memory would become a function of either: - the total number of inodes. - # inodes of combined working set assuming the (server) inode cache implements something like a LRU replacement strategy. I don't know if this is the case in the VFS, ext3 or knfsd. And this might make sense too: echo 0 >/proc/sys/vm/dirty_ratio # default 40 or 10 echo 0 >/proc/sys/vm/dirty_background_ratio # default 10 echo 0 >/proc/sys/vm/vfs_cache_pressure # default 100 Any opinion? -- Frank ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs