July 28, 2014

Who Will Support SMB 3.0, and Which Features Will They Support?

The Evolution of the SMB Protocol Series

I’m really thrilled about the improvements Microsoft is making to the core SMB protocol in Windows Server 2012. But it won’t really matter if nobody but Microsoft supports the new protocol. So I like to call out to all the enterprise storage vendors: Let me hear your support for SMB3.0!

What We Know so Far

Obviously, Microsoft is going to support SMB 3.0 in a big way. Windows Server 2012 will certainly be the premier server platform, especially for Windows 8 clients. But who else will support this new protocol?

Microsoft is going all-out to work with third parties, and is being unusually forthcoming with specifications and interoperability testing opportunities. I have seen reference to “plugfests” at the Storage Developers Conference and Build last year, as well as a special event on the Microsoft campus in early February. Specifications for SMB 2.2 (which has been renamed SMB 3.0) have been made available openly on the Microsoft website for months now, with frequent updates to match the progress of “Windows Next” development.

Microsoft’s presentation at SNIA SDC 2011 included contributions from Dennis Chapman of NetApp and John Hayden of EMC, so it’s a good bet that those two storage giants are on board to support SMB 3.0. Furthermore, NetApp’s Vaughn Stewart promised that version 8.2 of their core Data Ontap software will support the protocol when it is released this year.

Another clear vote of support came from the Samba team. A group of Samba developers participated in an “SMB 2.2 testing opportunity” at the Microsoft campus in late February. In a blog post, they outline the test setup and features tested (signing, persistent handles, and transparent client failover). So it seems very likely that Samba will also have at least partial SMB 3.0 support very soon.

Another player in the SMB market to announce support for SMB 2.2 is Likewise, makers of the popular server product used by many enterprise storage vendors. But Likewise was acquired by EMC’s Isilon division in late March. It is likely that many current customers will stick with Likewise for the time being, but the future is cloudier. At the very least, this indicates that Isilon will have solid SMB 3.0 support at some point.

Smaller companies may get SMB 3.0 support through Windows Server 2012, Likewise or Samba, but many are also working on their own homegrown support. Unlike SMB 1/CIFS, the simplified SMB2/3 protocol is much easier to implement successfully. This is why companies like Nimbus Data have come out publicly to endorse the protocol.

Which Features Will Be Supported?

SMB 3.0 is a big, complex protocol. It is unlikely that every implementation will support every feature. Indeed, certain elements (e.g. BranchCache and SMB Direct) are likely to be fairly rare while others (directory leasing and transparent failover) should be common.

If I could pick features to support, I would go with transparent failover and multichannel, along with the leasing improvements introduced since SMB 2.0. These would allow application server workloads in a fairly straightforward manner. The new client/server capabilities negotiation protocol is another must-have feature, since it allows pretty much everything else to function.

Encryption is another great feature on paper, but I’m not sure I would make it a priority. Application workloads are likely to be local, and network administrators have a fairly good handle on security in the data center. Plus, encryption was not even mentioned back at SDC, giving developers much less time to work on it. For these reasons, SMB 3.0 encryption should be late among third-party companies.

SMB Direct may see even less support among third-party array vendors. Most do not support InfiniBand, RoCE, or iWARP today, and those that do may find this new protocol difficult to add. In the long run, I do expect to see third-party SMB Direct-capable arrays appear, but for another year and not if customers don’t move in this direction.

VSS support is another big question mark. Although most NAS devices support snapshots today, it may be difficult to implement a “work-alike” VSS solution. Microsoft has already released documentation of this feature, however. The same could be said of BranchCache integration, though an open-source implementation is already available.

What about Everybody Else?

Although EMC and NetApp are big fish in the NAS market there are a great deal many more companies that could support SMB 3.0. BlueArc, now part of HDS, IBM, Dell, and HP are all major players. I would love to hear from those companies regarding SMB 3.0 plans.

Stephen’s Stance

Naysayers may point to previous Microsoft initiatives that failed to gain traction, but I think SMB 3.0 has a lot going for it. Microsoft’s openness with documentation and testing is a positive sign, as are commitments from major vendors like EMC, NetApp, and Samba. Add in the discontent with CIFS and existing work to implement SMB 2.0 and 2.1, and I expect widespread availability of at least some of the features of SMB 3.0 around the same time that Windows Server 2012 is released this summer.