From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rajat Upadhyaya" Subject: NFSv4 Active-Active Cluster Queries Date: Thu, 20 Jul 2006 00:11:26 -0600 Message-ID: <44BF6BE5.6FDC.007F.0@novell.com> References: <44BCC5620200007F0000E2C6@lucius.provo.novell.com> <44BCD1F80200007F0000E2CA@lucius.provo.novell.com> <44BCE7BB0200007F0000E2E7@lucius.provo.novell.com> <44BF54250200007F0000E3E0@lucius.provo.novell.com> <44BF5EF80200007F0000E3E4@lucius.provo.novell.com> <44BF5F580200007F0000E3E7@lucius.provo.novell.com> <44BF5F8B0200007F0000E3EA@lucius.provo.novell.com> <44BF607D0200007F0000E3ED@lucius.provo.novell.com> <44BF6B4F0200007F0000E3F6@lucius.provo.novell.com> <44BF6B870200007F0000E3F9@lucius.provo.novell.com> <44BF6BA30200007F0000E3FC@lucius.provo.novell.com> <44BF6BE60200007F0000E3FF@lucius.provo.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: neilb@suse.de, Olaf Kirch , nfs@lists.sourceforge.net Return-path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list2-new.sourceforge.net with esmtp (Exim 4.43) id 1G3RjI-000530-Pq for nfs@lists.sourceforge.net; Wed, 19 Jul 2006 23:09:49 -0700 Received: from lucius.provo.novell.com ([137.65.81.172]) by mail.sourceforge.net with esmtp (Exim 4.44) id 1G3RjE-0004wZ-Ue for nfs@lists.sourceforge.net; Wed, 19 Jul 2006 23:09:49 -0700 To: 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 Hi, I have been working on setting up NFSv4 in cluster scenario. But when it comes to an Active-Active setup, it seems there are a few problems. In Active-Passive case, the /var/lib/nfs directory itself is moved to shared storage & on the nodes in the cluster, symlinks are created pointing to the location on shared storage. This isn't possible in case of Active-Active setup. In this case, we will need to use scripts to merge the information in /var/lib/nfs from the failed node with that on the running one and then do a re-export. 1) From the High Availability wiki (http://wiki.linux-ha.org), I got to this page - http://chilli.linuxmds.com/~mschilli/NFS/active-active-nfs.html where a method of setting up Active-Active NFS failover was described. Basically a set of scripts is used to duplicate the rmtab entries on the node that takes over the process during failover. Will this method hold in case of NFSv4 too? What other data would need to be duplicated? 2) Assuming there are 2 nodes in a cluster, a client mounts different exports from both the nodes. Then if one node goes down, the other node takes over the failed node's IP & re-exports its exports. In this case, if (1) holds, what happens to the rmtab entry? Is it possible to merge the 2 entries? 3) Locking issues - revocation & reacquiring of locks. 4) I can see that there is some HA callout code in nfs-utils (under support). Is this applicable for NFSv4 also? Is my understanding here correct? If so, are there any work-arounds/solutions for the issues? Also, are there any other problems which I have missed out? Regards, Rajat ------------------------------------------------------------------------- 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