On Thu, Mar 01, 2012 at 10:35:38AM +0100, Daniel Schwager wrote: > Hi, > > we would like to setup a OCFS2 (Oracle Cluster File System 2) > cluster with 2 nodes, using a SAN as a shared storage. > Each of the nodes has access to the cluster filesystem. > > Now the question: Can we setup the running ndb-server > processes to be high-available (HA-linux, ...) ? > Of course, a ndb-client is connected to the nbd-server. > > ** Szenario1: Failure of one storage node: > Is there a chance to restart a nbd-server autoamtically (HA) on another > clusternode > without problems concerning the connection (means nbd-client does > not get in trouble) ? Of cource, the client must be configure for > write-through. > > ** Szeario2: Planed migration of all running nbd-servers to another > cluster node. > If szenario1 cannot be managed, is there a chance to migrate the > ndb-servers > to another node - of course, both nodes has no failure. May we have to > use LVS > for TCP session migration ?
There's been talk of a kernel patch that would block writes (rather than start issuing EIO or similar) until the process that had originally set up the connection would exit. This would allow an nbd-client to restart the same connection, or to connect to a fallback server. The former is implemented in nbd-client (the -persist option), the latter isn't. I don't know whether that has actually made it into the kernel, though. You may need to talk to Paul about that. Note also that until recently (i.e. before nbd 3.0), nbd-client erroneously would let the child live after a fork() call, rather than the parent; this would mean that with that version of nbd-client, this patch wouldn't even work in the first place. -- The volume of a pizza of thickness a and radius z can be described by the following formula: pi zz a ------------------------------------------------------------------------------ Virtualization & Cloud Management Using Capacity Planning Cloud computing makes use of virtualization - but cloud computing also focuses on allowing computing to be delivered as a service. http://www.accelacomm.com/jaw/sfnl/114/51521223/ _______________________________________________ Nbd-general mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/nbd-general
