From: Roger Heflin Subject: Re: fsid question Date: Tue, 27 Mar 2007 10:31:42 -0500 Message-ID: <460938DE.302@atipa.com> References: <46082D10.1060301@cse.yorku.ca> <46083474.8090906@redhat.com> <46091325.6050403@cse.yorku.ca> <46091498.6030706@moving-picture.com> <46091C41.6070908@cse.yorku.ca> <46092FC2.2080901@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: James Pearson , nfs@lists.sourceforge.net To: Wendy Cheng 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 1HWDeF-0007VC-JE for nfs@lists.sourceforge.net; Tue, 27 Mar 2007 08:31:48 -0700 Received: from 125.14.124.24.cm.sunflower.com ([24.124.14.125] helo=mail.atipa.com) by mail.sourceforge.net with esmtp (Exim 4.44) id 1HWDeE-0006pm-7V for nfs@lists.sourceforge.net; Tue, 27 Mar 2007 08:31:47 -0700 In-Reply-To: <46092FC2.2080901@redhat.com> 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 Wendy Cheng wrote: > 1. If server for whatever reason gets rebooted and somehow the device > major-minor number gets altered, the client that keeps the "old" file > handle will get a "stale file handle" error. Some of the NFS clients > will re-do lookup to obtain the correct FileHandle(s). Some of them will > simply fail. There is really not much you can do as a system administrator. I think this can also happen if you are using the major+minor numbers with say lvm, and change the order of the underlying LVM's, this might even be a risk with the fsid option if the underlying filesystem that it was supposed to be exporting fails to get mounted before the export. Server reboots, a different device is put at the same major and minor numbers than was there before,now the server now gets hammered with inode numbers that don't exist (valid range for filesystem, but don't exist on the "new" filesystem that is at the same major and minor numbers as the old one was). I have seen this actually completely use up all of the CPU on a NFS server, eventually causing it to be completely unusable, and of course the issue survives reboots of the server as the requests are coming from the clients, and the clients don't appear to ever give up, and if you have enough clients you can make the server unusable fairly quickly. I have seen the machine actually hang bringing up NFS from this. Roger ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs