Imagine there was someone many people loved to hate, but grudgingly loved just the same because of their incredible prowess. In Red Sox Nation, that would be Alex Rodriguez, who we follow year after year with a mix of admiration, envy, and anger as he seems to make all the right moves for the wrong team. Lots of IT people feel the same about Microsoft, whose runaway success is only slightly tempered by occasional schadenfreude when a misstep is made. In our little corner of the world, storage pros have even more reason to wonder how Microsoft can continue to make good move after good move.

It wasn’t always like this - be thankful if you don’t remember FTEDIT! But ever since Windows 2000, Redmond has made improvement after improvement, remaking “bad (SAN) citizen” Windows into Martha Stewart. But unlike the latter, Microsoft hasn’t called much attention to its skills, and this is a shame…

Take iSCSI - Microsoft was an early supporter of the protocol, releasing an excellent software iSCSI driver as a free download. They also bundle a limited (but continuously-improving) volume manager with all modern versions of Windows. Then there’s VSS, which is the first hardware-independent (even hardware-free!) snapshot API I know of. I’ve written articles (1, 2) on Windows storage technologies which go into these in more detail.

But one question that came up in my virtualization seminar made me realize that I forgot one key piece of Gates-tech: MPIO. See, Microsoft has also been bundling a free hardware-independent multipath I/O driver in server editions of Windows since 2003, but lots of folks haven’t gotten the memo. It’s good stuff: A generic driver with device-specific modules (DSMs) for different storage array and network types. MPIO handles transparent multi-path failover (for availability) and load balancing (for performance).

If you have iSCSI, you simply must try MPIO since Microsoft’s own free DSM supports about everything you need, and compatibility is required for logo support. And if you’re on Fibre Channel, you’re probably in luck, too, since most major vendors provide DSMs for their arrays (but some might not be free, I’m told).

So there you have it. Another excellent (and free!) Microsoft product that you (probably) never heard of, cutting out proprietary solutions (at least for Windows Server…)

I’ve been feverishly preparing for my upcoming TechTarget seminar series focused on storage virtualization, so I thought it might be interesting to post a few topics from the talk here on the blog.  If you’ll be in Washington DC on March 4, or Durham NC on March 6 and are interested in the world of storage and server virtualization, I’d love for you to register and attend this free seminar!

I’m kicking off with one of my favorite topics, logical volume management on servers. This is the longest-standing and most-successful face of storage virtualization, and the one I was first exposed to. Put simply, volume managers abstract block storage (LUNs, disks, partitions, what have you) into virtual “volumes” for use by the server. They look the same to the OS, and still need a filesystem, but are much more flexible, as we’ll see.

Volume managers are very common today - all modern OSes (except for that one from Apple!) have volume managers built in. Windows has the Logical Disk Manager, which I’m told was co-engineered (or something) with Veritas way back when and which I’ve covered in my Storage Magazine columns. Linux has an implementation of LVM, which I wrote something about way back when, and which has now not been supplanted by EVMS as had once been supposed. AIX it’s own twist on the original LVM, as does HP-UX. Solaris has the variously-named Solstice DiskSuite/Volume Manager which has evolved substantially in the 15 or so years I’ve been using it. And everyone has Symantec’s Veritas Volume Manager/Foundation Suite, which we in “the biz” view with considerable admiration and some skepticism, as is the case with all good front runners!

Folks mostly use volume managers for flexibility. It’s really quite amazing what you can do when your servers run them, enough that you often wonder how you got along without them!

• You can resize volumes (aka file systems or drives) on the fly (if your file system supports this as most modern ones do)
• You can protect data with RAID, even if your storage doesn’t support it (think bare disk drives)
• You can add storage capacity on the fly by concatenating new to old or (maybe) expanding existing stripes and RAID sets
• You can mirror volumes, create snapshots, and even replicate data to remote locations (this functionality varies by product, of course)
• One of the most powerful things (to me) was the ability to migrate live volumes from one storage device to another when making infrastructure changes

In short, volume management = server-based storage virtualization! So even if you were skeptical about the claims about storage virtualization, you might already be using it! Amazingly, a good volume manager can do anything a storage virtualization appliance or enterprise storage array can do. In fact, some virtualization appliances have more than a little volume management source code in them…

And the only cost for all this great stuff is the impact on your server’s CPU, memory, bus, access control, etc…

The chart below compares the major volume managers, and includes a little easter egg at the bottom… But we’ll cover that on another day.

XenSource just announced that they’ll embed Symantec-née-Veritas‘ server-side storage virtualization software into their server virtualization offering. This is great news, since server virtualization has boiling for more than a year now with precious little storage integration to be seen. Although XenSource is a distant second in the world of server virtualization, they’re close enough to put heat on leader, VMware. And every time an upstart prompts the market leader to innovate, I’m cheering. Plus, I’ve been a fan of VxVM for decades.

I for one was surprised at the small impact EMC has had on VMware. One systems administrator I talked to enthusiastically pointed out how great it was that big bad old EMC didn’t ruin VMware, but it cuts both ways. EMC has tremendous knowledge of the realities of managing storage in the enterprise, yet this hasn’t much rubbed off on VMware. After all, last I heard, they were still telling users to provision a single LUN for multiple virtual servers, and mixing OS and application data on the virtual C: drive…

Maybe we’ll see a response from EMC. EMC added volume management to PowerPath 4.0 back in 2003, and rumor had it they were developing their own full-featured multi-platform alternative to Veritas Volume Manager/Foundation Suite. Could this be headed into the VMware codebase? That would be a great way to gain some traction outside the storage space!