SMB 2.0: Addressing the Basics

The Server Message Block (SMB) file sharing protocol has been around since the dawn of time (anybody remember Windows for Workgroups?) With Longhorn operating systems (Server 2008, Vista, Windows 7), we have finally moved from SMB 1.0 to – everybody sitting down? – SMB 2.0. Wow… 15 years to update a file sharing protocol? This sort of thing certainly makes one cock an eyebrow when Microsoft discusses how innovative it is… Anyway, SMB 2.0 brings a number of improvements. It boasts lower overhead by permitting multiple requests to be bundled into a single packet, it includes support for much larger buffers and it permits a larger number of simultaneously open file handles. There are robustness improvements as well, that Microsoft claims will result in improved performance with intermittent links. The good news is that SMB 2.0 seems to perform significantly faster than SMB 1.0 under optimal circumstances. I’ve heard of improvements ranging from 50% faster to 3500% faster. (Testing is still appropriate however; I hear occasional stories about SMB 1.0 performing better than 2.0 in some environments.) The bad news is that, as you might expect, you have to have SMB support on both ends of the communications pipe for version 2.0 to kick into gear. For example, if you have a Vista client but a 2003 Server, you won’t get SMB 2.0.