From: Greg Lindahl Subject: Re: Soft vs Hard mounts Date: Fri, 16 May 2003 14:50:18 -0700 Sender: nfs-admin@lists.sourceforge.net Message-ID: <20030516215018.GB1879@greglaptop.internal.keyresearch.com> References: <482A3FA0050D21419C269D13989C61131274DD@lavender-fe.eng.netapp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: To: nfs@sourceforge.net In-Reply-To: <482A3FA0050D21419C269D13989C61131274DD@lavender-fe.eng.netapp.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 Fri, May 16, 2003 at 09:13:18AM -0700, Lever, Charles wrote: > recently trond mentioned that this issue was not likely to > be addressed until after 2.6 because it requires architectural > changes in the VFS layer and probably a new type of semaphor > implementation. Well, some of the issues might be separate, and some have workarounds. For example, if stat() on a nfs mountpoint causes a process to hang, and you have processes like ssh which want to make sure your conf file is secure by walking the path back to /, there is a workaround of putting each mount point in its own directory: /home/foo/foo /home/bar/bar You'd also want to look into what the Linux automounter does. It looks different from what I'm used to. > 3. make soft mounts work more reliably by purging a file's > page cache contents when a soft timeout occurs > > 4. educate sysadmins how to make soft mounts more reliable > by thoroughly testing to determine a reasonable set of > mount options. Option (3) might make network congestion much worse, and turn congestion into failure. (4) is really hard, because it's hard to thoroughly test many different types of activity and congestion. Distributed system people generally eventually end up thinking that introducing any timeout will always result in congestion and odd circumstances turning into failures. I vastly prefer systems which have the behavior of "hard,intr". greg ------------------------------------------------------- This SF.net email is sponsored by: If flattening out C++ or Java code to make your application fit in a relational database is painful, don't do it! Check out ObjectStore. Now part of Progress Software. http://www.objectstore.net/sourceforge _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs