On ti. 23. okt. 2012 kl. 20.33 +0200, Brian Candler wrote: > On Tue, Oct 23, 2012 at 01:55:01PM +0200, Runar Ingebrigtsen wrote: >> to enable NFS state transfer between hosts in a failover SAN, it is >> necessary to have the NFS state data on the exact same blocks on both >> storage nodes: > > You are reading a document for something which is not glusterfs. I'm sorry - I am aware of that. The part of the document I was meaning to reference was the block-by-block replication that was pointed out as a requirement for NFS connection handover. I should have pointed out what I meant better. >> Can I somehow enable block-for-block replication with GlusterFS? > > No. You are reading documentation for something completely different: a pair > of machines synchronised at the block level using DRBD, in a master/slave > configuration (that is: all writes must be made on the master side, and the > block changes are replicated a la RAID1 but over a network). Hm. I don't see how your reply indicates the lack of block-by-block replication in GlusterFS. > I suggest you ask a different question: "can I have failover between two > gluster NFS servers without getting stale filehandles?" Good point. I'm happy to annouce that it did turn out that, indeed, you can. The reason it didn't work was a User Error. When you use UCarp for failover between two GlusterFS servers, the Virtual IP address stops responding for about 5 seconds when you unplug the UCarp master node. It then takes the NFS client about 45 seconds more before it is able to use the GlusterFS/NFS mount on the UCarp secondary node. > I don't know the answer to that myself, but I have seen messages which > suggests others may have it working: > http://gluster.org/pipermail/gluster-users/2012-June/010700.html Thank you. -- Best Regards Runar Ingebrigtsen
