Tag Archives: Hyper-v

Does “Shared Nothing” Migration Mean the Death of the SAN?

You’ve probably heard that Hyper-V in Windows Server 2012 supports what Microsoft is calling “Shared Nothing” live migration. You can see a demo of that here, in a video that was posted on a TechNet blog back in July:

Now don’t get me wrong - the ability to live migrate a running VM from one virtualization host to another across the network with no shared storage behind it is pretty cool. But if you read through the blog post, you’ll also see that it took 8 minutes and 40 seconds to migrate a 16 Gb VM. (And I don’t know about you, but many of our customers have VMs that are substantially larger than that!) On the other hand, it took only 11 seconds to live migrate that same VM running on the same hardware when it was in a cluster with shared storage.

So I will submit that the answer to the question posed in the title of this post is “No” - clearly, having shared storage behind your virtualization hosts brings a level of resilience and agility far beyond what Shared Nothing migration brings. Still, for an SMB that has a small virtualization infrastructure with only two or three hosts and no shared storage, it’s a significant improvement over what they’ve historically had to go through to move a VM from one host to another: That has typically meant shutting the VM down, then exporting it to a storage repository that can be accessed by the other host (e.g., an external USB or network-attached hard drive), then importing it into the other host’s local storage, then booting it up…that can easily take an hour or more, during which time the VM is shut down and unavailable.

So Shared Nothing migration is pretty cool, but, as Rob Waggoner writes in the TechNet post linked above, don’t throw your SANs out just yet.

Just Sign the Check Right Here - We’ll Fill In the Amount Later

Back in the old days of minicomputers and mainframes, we used to joke about IBM’s ability to, for all intents and purposes, get the customer to sign a blank check. They were better than anybody I’ve ever seen at getting people to commit to a solution when they really had no idea what the ultimate cost would be - and they were successful because of another cliche (which became a cliche because it was so accurate): “Nobody ever got fired for buying from IBM.” The message was basically, “Yes, we may be more expensive than everybody else, but we’ll take care of you.”

For the most part, those days are long gone, which made it all the more amazing to me to read that VMware is adopting per-VM licensing for most of its management products.

The article nails the basic problem with this licensing approach:

You know how many processors you have on a system, and that’s a fixed number. But the number of VMs on one host — let alone throughout your entire infrastructure — is regularly in flux. How do you plan your purchasing around that? And how do you make sure you don’t violate your licensing terms?

Hey, it’s easy - you just let VMware tell you what to put on your check at the end of the year:

You estimate your needs for the next year and buy licenses to meet those needs. Over the course of those 12 months, vCenter Server calculates the average number of concurrently powered-on VMs running the software. And if you end up needing more licenses to cover what you used, you just reconcile with VMware at the end of the year.

And, before you ask, no, you don’t get money back if you use fewer licenses than you originally purchased.

Sounds to me like a sweet deal - for VMware.

By comparison, the most expensive version of XenServer is $5,000 per server (not per processor, not per VM), and all of the management functionality is included. And the basic version of XenServer, which includes live motion, is free, and still includes the XenCenter distributed management software. (Here’s a helpful comparison chart of which features are included in which version of XenServer.)

A number of years ago, I attended a seminar that discussed the product adoption curve, and how products moved from the “innovation” phase to the “commodity” phase. The inflection point for a particular market was referred to as the “point of most” - where most of the products met most of the needs of most of the customers most of the time. When this point is reached, additional feature innovation no longer justifies a premium price.

The fact is that XenServer and Hyper-V are rapidly achieving feature parity with VMware. If we haven’t reached the “point of most” yet, we certainly will before much more time goes by. So even if you have a substantial investment in VMware already, at some point you have to re-examine what it’s costing every year, don’t you? Or are you OK with just signing a check and letting them fill in the amount later?

Microsoft Takes a Step In the Right Direction

The big Webcast just wrapped up, and will be available for replay shortly at http://www.desktopvirtualizationhour.com. Click on the “videos” tab to get to the selection of recorded videos. Several changes were announced. Unfortunately, they don’t become effective until July 1, but you can’t have everything.

  • VECD is dead, long live the VDA. For all practical purposes, the VECD license is history. Effective July 1, if your client desktop is a PC that’s covered by Software Assurance, you will no longer have to purchase a VECD license to access a virtual Windows Desktop. That saves you about $23/device/year.

    If your client device is not covered by SA (e.g., a thin-client device), you will now be required to purchase the new “Virtual Desktop Access” (“VDA”) license, which will cost about $100/device/year. That also represents a savings of $20/year or so compared to the old VECD pricing model.

    In both scenarios, the “primary user” of that client device now has the rights to access corporate VDI desktops and Microsoft Office applications from other client devices, such as home PCs, Internet cafes, hotel business centers, etc.

  • Windows Server 2008 R2 SP1 will have a couple of new features that will make VDI a friendlier place to go:
    • Dynamic Memory - Provided your guest operating systems support “hot add” for memory, you will be able to configure your Hyper-V host with minimum and maximum memory limits for the guests. So if a VM that’s serving a power user needs more RAM, more RAM will be dynamically allocated from the host server’s memory pool. When that additional RAM is no longer needed, it will be returned to the pool. Note that this assumes that there is unallocated RAM available - this is not the same thing as “memory overcommit.” This should increase VM density and require fewer Hyper-V hosts to support a given number of virtual desktops. Note also that Windows XP does not support “hot add,” so that’s just another reason to make the move to Win7 when you virtualize.
    • RemoteFX - This is a set of technologies that have evolved from Microsoft’s acquisition of Calista Technologies a couple of years ago. It’s primarily a set of enhancements to the RDP protocol, but the graphics virtualization enhancements will also benefit virtual Win7 PCs that are running on a 2008 R2 SP1 Hyper-V host. The performance that was demonstrated during the Webcast was pretty impressive, but in addition, Citrix announced that the “HDX” technology in XenDesktop would be enhanced so it could detect when the RemoteFX technology was present, and leverage it to make graphics performance even better. You’ll find more information on RemoteFX over at the Windows Virtualization Team Blog.
  • The Citrix/Microsoft Partnership is still going strong, and a couple of new promotions were also announced today:
    • “Rescue for VMware VDI” - which is targeted squarely at people who have started to deploy VMware View, and ran headlong into problems with scalability, user experience over WAN links, etc. These customers will be able to trade in up to 500 VMware licenses for the same number of Microsoft VDI Standard Suite subscription and Citrix XenDesktop VDI Edition annual licenses at no cost. Note, however, that these are annual, subscription-based licenses, so they are going to start costing you money after the first year.
    • “VDI Kick Start” - Eligible customers can pay only $28 per device for up to 250 devices to license the Microsoft VDI Standard Suite subscription and the Citrix XenDesktop VDI Edition annual licenses, allowing you to roll out a 250-seat VDI deployment for only $7,000 in licensing costs - roughly a 50% savings. Again, note that these are annual subscription-based licenses, so you’ll start paying the regular price after the first year. Still, that’s a pretty aggressive offer.

The big loser in today’s announcements? VMware. In addition to the trade-in offer, Microsoft made it very clear where they stood. I submit for your consideration a screen cap of the Q&A thread from the Webcast:

If there was any doubt before about where the battle lines are drawn, there shouldn’t be anymore.

In closing, here are a couple of other links you may want to check out:

Bottom line: While I didn’t get everything I’ve complained about in the last couple of blog posts, and I’ve got to wait a few months for some of the announcements to be effective (nothing new about that), it was not a bad day at all. Definitely a step in the right direction.

Understanding Microsoft Server Virtualization Rights

So, grasshopper, you have decided to take the plunge and virtualize your server infrastructure. Someone (perhaps us) explained the business benefits of virtualization, you decided that it made sense, and that it’s time to make the move. But do you know how virtualization will affect your Windows Server licensing model?

The first thing you need to know is that Windows Server licenses are assigned to physical hardware, not to server workloads. When you purchase a license, you must “assign” that license to a physical server. How do you do that? Well, in today’s world, there is no formal process for doing that, although if it makes you feel better, you can write it down somewhere.

You may assign more than one license to a physical server, but you may not assign the same license to more than one physical server. You may reassign a license from one physical server to another, but not more frequently than every 90 days, unless the server it was assigned to is being retired due to “permanent hardware failure.”

Sound reasonable so far? Of course it does. Right up until the license model runs head-on into one of the coolest features of virtualization: live motion. Most virtualization platforms, including Microsoft’s Hyper-V R2, allow you to easily move a virtual server from one physical host to another. Great feature, right? But if you do it, you may have just violated your Windows license agreement.

I say “may” because different versions of Windows Server come with different virtualization rights. For example, a Windows Server Standard license can be used to run one physical instance of Windows (and by “physical instance,” I mean Windows is installed directly on the hardware) or one virtual instance of Windows, but not both - unless the physical instance is being used solely to manage the virtual environment.

Let me say that another way: If you buy a single license for Windows Server Standard Edition with Hyper-V, you can install it directly on the hardware without bothering with the Hyper-V role. Or you can install the Hyper-V role, have one virtual Windows Server running on top of Hyper-V, and use the physical instance exclusively to manage the virtual instance. Of course, you haven’t really gained anything by doing that…but you can purchase additional copies of Windows Server Standard, assign them to the same physical host, and run more virtual servers on Hyper-V.

Thinking this scenario through, then, if you currently have a bunch of physical Windows Servers - each licensed with Windows Standard Edition - and you want to virtualize them all, that’s no problem. You can reassign your server licenses to your virtual hosts and be perfectly legal. As long as you don’t move a server from one host to another. But if all you own are Standard Edition licenses, and you move a server from one host to another, you’ve just violated the license agreement - unless you own a “spare” server license that you have “assigned” to the target server (the host you’re moving it to) but that is not being used.

Now, in the scenario I just described, it’s possible that the most cost-effective thing you could do is to just buy a few additional licenses as “spares” rather than re-licensing your entire environment. But let’s move ahead - once we’ve covered the other Windows editions that are available to you, you’ll be better able to decide what makes financial sense for your project.

Windows Server Enterprise Edition comes with expanded virtualization rights. Each Enterprise Edition license gives you the rights to run one physical instance and up to four virtual instances on the physical host to which it is assigned. Once again, if you want to run all four virtual instances, then the physical instance may only be used to manage the virtual environment. If you want to run other services on the physical instance - and that’s actually fairly common in a Hyper-V deployment - then you only get to run three virtual instances. And you may not split the license across multiple physical hosts.

The “estimated retail price” (just the license, no Software Assurance, assuming Open Business pricing) for Windows Enterprise is $2,358, vs. $726 for Windows Standard. So Enterprise is less expensive than four copies of Standard. Therefore, if you need to buy new licenses (perhaps you’re upgrading from Server 2003 to Server 2008 as part of your virtualization project), it may make sense in a small environment to buy a copy of Enterprise Edition for each virtual host, and perhaps supplement it with a few spare copies of Standard Edition. Here’s an example:

Let’s say you have a total of nine physical servers today, and you want to virtualize them on three dual-processor virtualization hosts. (You could probably run them on two hosts, but if one failed, it might be a stretch to run all nine on one host. If you start with three hosts, and one fails, you still have two to carry the load.) You could buy nine new copies of Windows Standard Edition for $6,534, but you’d have no flexibility to use live motion to move things around. On the other hand, you could buy three copies of Enterprise Edition for your three hosts for $7,074, and effectively have one “spare” instance on each host that’s available for moving a virtual machine from one host to another.

Of course, that may not be quite enough if you want to completely unload one of your servers (perhaps to take it off-line for maintenance), because unless you’re prepared to shut down one VM completely, you’re going to need to run five VMs on one of your remaining servers. Since you may not know in advance which server needs to assume the extra VM workload, you could just buy three additional copies of Standard Edition, and assign one to each host. That would push your total license acquisition cost to $9,252, but you would then be licensed for five VMs on each of your hosts.

The ultimate in flexibility is Windows Server Datacenter Edition. Datacenter Edition is licensed per processor socket rather than per physical host, but includes unlimited virtualization rights. You can run as many VMs on your hosts as they’re capable of running, and move them around to your heart’s content. If you just don’t want to worry about what’s running where or whether or not it’s technically legal to move a given VM around, this is the license model to use.

Of course, this is also the most expensive edition of Windows. The estimated retail price for Datacenter Edition is $2,405 per processor socket (regardless of the number of cores per processor). So it would cost $14,430 to license three dual-processor servers with Datacenter Edition. This probably isn’t cost effective if you’re only virtualizing nine servers. However, if you have lots of servers, and many of them are fairly lightly loaded (in terms of processor utilization), the picture could change. If your average consolidation ratio is greater than or equal to four servers per physical processor then Datacenter Edition becomes the most cost-effective license.

In fact, if you’re even close to that 4:1 ratio, you should strongly consider Datacenter Edition, for two reasons:

  1. Windows environments inevitably grow. However many servers you have today, you’re probably going to have more of them a year from now. With Datacenter Edition, you can continue to fire up new servers to the limits of your hardware without having to buy more server licenses.
  2. AMD already has six-core processors. You know the “arms race” between Intel and AMD will continue. So the number of servers per processor that you can reasonably expect to support will continue to increase as the processors themselves become more powerful and contain more cores, and as this happens, Datacenter Edition will look better and better.

Note that everything we’ve discussed holds true if you’re virtualizing on XenServer or VMware rather than on Hyper-V. The only difference is that you won’t be using any of the allowed physical instances of Windows.

If you want to delve deeper into this issue, you can download a copy of the Microsoft Product Use Rights document from their Web site. Happy virtualizing!

Time To Switch Virtualization Platforms?

Have you been considering moving from VMware ESX or vSphere to either Citrix® XenServer™ or Microsoft® Windows® Server 2008 Hyper-V™ - but been concerned about exactly how to go about it? Knowing what tools to use to make the migration go smoothly is often a major concern. Also, what kind of support can you get during the transition? And structured training on a new platform is not inexpensive, either. Now Citrix is trying to eliminate these obstacles with a new promotion that runs through March 31, 2010.

On October, 14, 2009, Citrix announced a new program called Project “Open Door”. Customers who switch existing VMware servers to XenServer or Hyper-V, and add Citrix Essentials™ for advanced virtualization management, will receive additional technical support, training, and conversion tools from Citrix at no additional cost.

The Project Open Door promotion will be effective worldwide from October 1 – March 31, 2010. Customers who decommission five or more VMware vSphere 4 or VI3 servers and replace them with XenServer or Hyper-V plus the Citrix Essentials solution, receive the following:

  • A free five incident support pack (5 by 8 hours) for every five servers converted
  • A voucher for six hours of online training for every five servers converted
  • Free migration tools for seamlessly transferring virtual machines from VMware to XenServer or Hyper-V

Check out http://www.citrix.com/opendoor for more information on the program. If you’re seriously considering making the switch, this just might be the time to do it.