Following up on my post Windows Server 2012 NIC Teaming: So Easy a Caveman Can Do It?, a new post by Jose Baretto on the Windows Server team has another great post on SMB 3.0 which provides details on one of the key design points I mentioned in my NIC teaming post, namely what features are available given the hardware you have chosen, and which features can be used together. Jose talks about the new SMB Mulitchannel capability which improves both performance and availability of SMB 3.0 traffic in Windows Server 2012 and Windows 8. While SMB 3.0 Multichannel can be used in conjunction with NIC Teaming and SMB 3.0 Multichannel can be used with RDMA, the three cannot be used together, namely you cannot use NIC Teaming with RDMA. Does this mean that if you want the performance of RDMA for your SMB 3.0 traffic you are out of luck in terms of high availability? Heck no! That’s where the SMB Multichannel plus RDMA scenario comes in. SMB 3.0 Multichannel provides resileincy for SMB connections when used with multiple NICs and yes those NICs can be RDMA capable.
That is why in my post Windows Server 2012 – Private Cloud Nirvana?, I included the diagram below which shows what I think will be one of the more common design patterns for Hyper-V and Scale-Out File server clusters.
Note that between the Scale-Out File Server cluster and the Hyper-V cluster, I show the usage of RDMA capable NICs. You’ll also note that I do not show NIC Teaming there as you now know those two technoligies cannot be used together. As you see, I did indicate the usage of SMB 3.0 Multichannel there to enable high availability and bandwidth aggregation for those connections. The combination provides extreme levels of performance. That covers the Hyper-V to File Server side of the design. For the LAN side, NIC Teaming is utilized as in most cases, RDMA is not required for the connectivity to Hyper-V hosts and VMs. For some early examples of how much performance can be driven across the SMB 3.0 Multichannel and RDMA solutions, check out Mellanox’s announcements this week: Mellanox FDR 56Gb/s InfiniBand Accelerates Windows Server 2012 File Server Performance for Database and Cloud Deployments. That’s an insane amount of storage bandwidth!
Again, the main things to be thinking about right now are you future hardware architectures and how they mesh with the Windows Server 2012 features you need to meet your requirements. I’ll be covering that as much as I can here.