From: James Pearson Subject: Re: NFSv4 and client caching to local disk? Date: Mon, 31 Mar 2003 13:33:39 +0100 Sender: nfs-admin@lists.sourceforge.net Message-ID: <3E8835A3.D5E64144@moving-picture.com> References: <6440EA1A6AA1D5118C6900902745938E07D55473@black.eng.netapp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: nfs@lists.sourceforge.net Return-path: Received: from mpc-26.sohonet.co.uk ([193.203.82.251] helo=moving-picture.com) by sc8-sf-list1.sourceforge.net with esmtp (Exim 3.31-VA-mm2 #1 (Debian)) id 18zyUh-00049N-00 for ; Mon, 31 Mar 2003 04:34:31 -0800 To: "Lever, Charles" 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: "Lever, Charles" wrote: > > hi james- > > > I'm trying to find out more about 'cachefs' type file systems > > that can > > cache NFS data to a client's local disk - I've come across a > > couple of > > references that seem to indicate that this may be possible with NFSv4. > > > > Does (will?) the Linux NFSv4 client support this feature? > > Sun implemented cachefs on Solaris for earlier versions of NFS. > it really has nothing to do with which version of NFS that is > in use. I've briefly looked at this on IRIX clients some time ago - but we don't have many IRIX boxes in use now. > there is sporadic interest in a cachefs on Linux, and i know of > at least one generic prototype. a specific implementation of > client-side disk caching that is available today is contained > in the Linux OpenAFS client (known as the AFS cache manager). I have done some limited searching of the net for info and come across a few attempts with earlier kernels - and I am aware of some the issues/problems associated with doing this. > cachefs becomes rather more interesting when used in conjunction > with NFSv4 file delegations -- that makes NFS behave in a fashion > similar to AFS client-side disk caching with callbacks. My hopes were raised as the NFSv4 specs suggest that low level support for client disk caches is available - rather than being a 'bolt-on' for earlier versions - hence my question. > there currently is no explicit plan to implement cachefs by the > team that is working on NFSv4 for Linux. a disk cache has > rather limited usefulness compared to a memory cache. what is > your application for it? Mainly for reading large files that don't change (much) - i.e. effectively in a read-only mode. The total size of the required files is greater than the clients memory size - in fact any disk caching of NFS data doesn't necessarily need to survive a reboot of the client, so caching NFS file system data to swap could be enough for my needs ... James Pearson ------------------------------------------------------- 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