From: Bogdan Costescu Subject: Re: NFSv4 and client caching to local disk? Date: Tue, 1 Apr 2003 21:05:36 +0200 (CEST) Sender: nfs-admin@lists.sourceforge.net Message-ID: References: <20030331103850.1f40a7f9.jake@dtiserv2.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: James Pearson , , Return-path: Received: from mail.iwr.uni-heidelberg.de ([129.206.104.30]) by sc8-sf-list1.sourceforge.net with esmtp (Exim 3.31-VA-mm2 #1 (Debian)) id 190R51-0002kF-00 for ; Tue, 01 Apr 2003 11:05:55 -0800 To: Jake Gold In-Reply-To: <20030331103850.1f40a7f9.jake@dtiserv2.com> Errors-To: nfs-admin@lists.sourceforge.net List-Help: List-Post: List-Subscribe: , List-Id: Discussion of NFS under Linux development, interoperability, and testing. List-Unsubscribe: , List-Archive: On Mon, 31 Mar 2003, Jake Gold wrote: > I have a FAS940 with a cluster of Linux machines mounting _read-only_ > volumes over NFSv3. My situation is the same as James Pearson's....those > machines read large, rarely modified files, where memory caching doesn't > help a whole lot. It would be very nice to be able to have my > under-worked local disks take some of the load off the filer. How about doing it in the application itself ? Often application has more knowledge about what it needs than the OS. So in a case like the one that you described I would copy the rarely modified file(s) to the local disk and just before accessing them in any way check to see if they were modified. If this is true read-only you don't even need to check this, but otherwise you could use some rsync-style transfer to get only the parts that were modified (assuming that new data is not completely different)... Modification can be detected from the file attributes, md5sum or something else. The application level caching is more interesting when the cache size is smaller than the data set. The OS would typically use LRU strategy to make some more room in the cache when needed, but this is not always the best approach - the application is the only one that can have some more information about what data will be needed in the near future. -- Bogdan Costescu IWR - Interdisziplinaeres Zentrum fuer Wissenschaftliches Rechnen Universitaet Heidelberg, INF 368, D-69120 Heidelberg, GERMANY Telephone: +49 6221 54 8869, Telefax: +49 6221 54 8868 E-mail: Bogdan.Costescu@IWR.Uni-Heidelberg.De ------------------------------------------------------- This SF.net email is sponsored by: ValueWeb: Dedicated Hosting for just $79/mo with 500 GB of bandwidth! No other company gives more support or power for your dedicated server http://click.atdmt.com/AFF/go/sdnxxaff00300020aff/direct/01/ _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs