vTeardown

Microsoft used their TechEd conference a couple weeks ago to announce a few new features in their yet-to-ship Hyper-V and SCVMM R2 updates.  One addition in particular caught my attention.  It’s called “Quick Storage Migration” and the word “Quick” in the title is what perked up my ears.  Those of you working with the current versions of Hyper-V and SCVMM know that “Quick” is Microsoftspeak for “not quite live.”  Right now, the only way to migrate a running Hyper-V virtual machine is with their “Quick Migrate” feature, which forces VMs to endure relatively long downtimes, enough to cause TCP/IP connections to timeout and user connections to drop.

When Microsoft was rolling out Hyper-V and Quick Migration, they were adamant in telling users that Quick Migration was all they needed.  I clearly remember their representatives claiming that migrating a VM should be a rare event, so the downtime was tolerable.  Hyper-V users were told that if they needed to migrate VMs more often than once a month, they were at fault for making mistakes in their capacity planning and VM placements.  It was a very transparent attempt to downplay the absence of true live migration in their product.  Microsoft was effectively telling customers, “You don’t really need that live migration stuff.  It’s overkill and nobody really uses VMotion anyway.”

You can’t blame Microsoft for making excuses for Quick Migration, but claiming that nobody uses VMotion just elicited chuckles from the audiences at their conferences — most whom indicated they were VMware users whenever a “show of hands” poll was taken.  The truth is 70% of VMware customers are using VMotion in production and they rave about the flexibility it gives them.

The truth comes out

Now that Microsoft has live migration on their Hyper-V roadmap, we’re starting to learn that they never really thought much of Quick Migration themselves.  I heard Mark Russinovich, one of their technical luminaries who gave a talk about Hyper-V R2 futures, actually come out and say what we all knew to be true, “Quick Migration was our first attempt to do a live migration, and to put a nice spin on it, we called it Quick Migration. [...] Even though we said, [...] ‘trust us this is really cool, this is what you want, you don’t want instant, that’s not as good as this, this is quick,  but people didn’t seem to buy that, so we ended up [...] implementing live migration, so that Quick Migration stuff is crap, this is really good.’”  Mark’s honesty got some laughs from the packed session, but it puts us on notice that we should be skeptical when Microsoft tags a feature as “Quick”.

Microsoft’s new “Quick Storage Migration” promised for SCVMM R2 is just such a feature to approach carefully.  Microsoft is positioning it as equivalent to the VMware vSphere Storage VMotion feature, which does true live migration of a VM’s virtual disks to another storage location with zero VM downtime.  As you might infer from the name, “Quick Storage Migration” forces a Hyper-V VM offline during the move.  The downtime occurs while a snapshot made of the VM at the start of the move is reverted back to the primary virtual disk once it’s copied to the new storage location.  Microsoft didn’t say how long that downtime would be, but as we saw with Quick Migration, anything longer than a few pings will result in timed out connections.

Look out, more “Quick” is on its way

It’s not surprising to see Microsoft reaching for their “Quick Migration” marketing playbook as they try to explain away the limitations of Quick Storage Migration.  Once again, they’re asking customers to accept “Quick” as good enough and they’re even laying a guilt trip on anyone who has the temerity to ask for true live storage migration.  In Jeff Woolsey’s session at TechEd, we were told not to worry about the downtime because, “How often do you do maintenance on a SAN?  Hopefully that answer is very rarely, because if it’s any more than that, then you probably misconfigured your SAN.”  VMware customers who have been using Storage VMotion since VI3.5 would certainly disagree.  They use Storage VMotion for lots of reasons including rebalancing storage, relocating VMs when business units reorganize, and maybe they do misconfigure a SAN once in a while, but with Storage VMotion, fixing it is no big deal.  With Microsoft’s Quick Storage Migration, you’ll need to schedule a maintenance downtime window for any of those use cases.

By now you’ve probably detected a pattern in Microsoft’s Hyper-V/SCVMM maturation as shown by these “Quick” features.  First, they roll out a deeply flawed “me too” feature while telling customers their implementation is good enough and they don’t really need the fully baked version available from VMware.  Next, any customers asking for the full feature are told they only want it because they are doing something wrong in managing their systems.  Finally, when Microsoft gets around to offering the real deal, customers are told that the initial, crippled feature was “crap” all along.

Don’t let them “Quick” on you again

Fortunately, virtualization users don’t have to put up with such treatment.  VMware has been delivering virtualization innovations, rather than asking customers to meekly wait while they catch up to the other guys.  Once Microsoft has a look at the breakthroughs in vSphere like Fault Tolerance, vShield Zones, Data Recovery, Distributed Power Management, Host Profiles and vNetwork Distributed Switches, I wonder which of them will get the “Quick” treatment in some future Hyper-V release.

vTeardown won’t be just another virtualization blog.  We’ll be writing about hypervisors and virtualization management tools, but the important difference we’ll be bringing to our readers is a focus on the technology’s ability to meet customer demands based on actual hands-on usage and not vendor datasheets and press releases.

All of us on the vTeardown team are part of VMware’s Server Business Unit where part of our job is keeping tabs on the VMware alternatives that our customers might also be evaluating.  To do that, we don’t rely on just the vendor documentation.  Instead, we install those products on servers, networks and storage hardware like those found in production datacenters, and then we put them through every test we can think of – we “tear them down” – to see if they can hold up to the needs of real users.  We’ve already uncovered lots of issues you’ll want to know about and you can look forward to learning about them in this blog.

We’re proud of VMware’s virtualization products and their production-proven reliability and performance.  However, we’re not the only provider of x86 virtualization platforms any longer and we need to keep making our products better than the alternatives if we want to maintain the hard-earned loyalty of our customers.  The vTeardown lab is where we compare our products to those alternatives to ensure we keep providing a better platform.  Our findings help our customers know when our competition is making claims in their datasheets that their products can’t deliver.

You might already know one member of our team from his very popular VCritical blog.  Eric Gray is one of our virtualization management experts and he’s been opening lots of eyes to the real world limitations of Microsoft’s offerings in that space.  At vTeardown, we aim to do the same for hypervisors and other management tools.  So look forward as our team – Michael Hong, Kayvan Montakhab and I – sheds some light on the real capabilities of the products out there in the virtualization market.