I have been chomping at the bit to test VMware on dNFS on EMC NAS for a couple of reasons. A number of my customers who are looking at EMC NAS in particular the NS20 would like to consolidate storage, servers, file services, etc… on to a unified platform and leverage a single replication technology like Celerra Replicator. dNFS may offer this possibility, .vmdks can now reside on the a NFS volume, CIFS shares can be consolidated to the the NS20 and all can be replicated with Celerra Replicator. The only downside to this solution that I can see is right now the replicated volumes will be crash consistent copies but I think with some VMware scripting even this concern can be addressed. I hope to stand this configuration up in the lab in the next couple of weeks so I should have more detail and a better idea of is viability shortly. You may be wondering why this post entitled Oracle Storage Guy…… the answer is I was searching the blogsphere for an unbiased opinion and some performance metrics of VMware and dNFS and this was the blog that I stumbled upon.
The performance numbers I have seen for VMware on dNFS come very close to the numbers I have seen for iSCSI, both technologies offer benefits but for the use case I mention above dNFS may become very compelling. I recommend reading this post Oracle Storage Guy: Direct NFS on EMC NAS, is offers some great commentary on the performance characteristics and benefits of dNFS.