Microsoft

Much has transpired since yesterday, when I urged VMware to join the SVVP and get their software validated for full support by Microsoft. Since that time, it has come to light that VMware has joined the SVVP, although a formal announcement has not yet been made, and Microsoft has announced some significant licensing changes regarding virtualization. I’ve been reading the various announcements and analyses regarding this information and I thought it might be beneficial to try to pull all this together.

First, refer to Patrick O’Rourke’s blog entry, which does a great job of summarizing the need for application mobility licensing. Clearly, customers needed the ability to move applications freely between physical servers, and Microsoft themselves needed to allow customers to do this now that they have a more robust virtualization solution in place (Hyper-V and SCVMM 2008). While the licensing changes do benefit all virtualization vendors, it’s important to note that Microsoft needed these changes for themselves as well.

Patrick’s post also brings to light that while VMware has joined the SVVP, cooperative support is not yet in place. That won’t come until validation via SVVP is completed, which may take some time. The joining of SVVP was necessary, as it is merely one step toward a larger goal.

However, there’s more here than perhaps many people are realizing. Fortunately, there are a number of sites out there pointing out important caveats to the new licensing changes:

• Rich at VM /ETC correctly points out that the new licensing does not apply to the Windows Server OS itself. So you are still going to have problems with VMware HA and VMware DRS automatically moving VMs from server to server unless you use Windows Server Datacenter Edition (see below).
• Chris Wolf points out (both on his personal blog as well as the Data Center Strategies blog) that the lift on the 90-day license transfer does not apply to licenses purchased outside of a volume license agreement. Using OEM licenses? Then you’re out of luck; those licenses still fall under the old restrictions.
• eWeek’s Joe Wilcox points out that because the Windows Server OS isn’t included in the 90-day license relief, some customers will simply license Windows Server Datacenter Edition for every CPU in their data center. Of course, the fact that you now get Hyper-V for free with Windows puts Microsoft…ahem, ahead of the game, shall we say? Read Joe’s full report here.

So, while Microsoft’s licensing changes are a good first step, there’s still more work to be done. Let’s applaud the changes, which were necessary, but let’s continue to press Microsoft to fix the issues that remain.

To Whom It May Concern at VMware:

If I had to choose only one thing that I wanted VMware to be sure to do in the next few months, here is what it is: join the Microsoft Server Virtualization Validation Program and get VMware Infrastructure validated. No, I don’t want you to finish VI4. No, I don’t want you to concentrate on Continuous Availability. I want you to join SVVP.

Why? I can answer that question with only one word: support.

As fully expected now that Microsoft has a more robust virtualization solution, there has been a sudden about-face on the use of server virtualization in conjunction with their products. Consider this announcement regarding support for Exchange Server 2007 SP1 (quoting from this blog entry):

Microsoft now supports Exchange Server 2007 SP1 running Hyper-V or hypervisors validated under the Microsoft Server Virtualization Validation Program (SVVP).

I can hear you at VMware now: “We don’t need to validate our technology by signing up for some program run by Microsoft! Our hypervisor is the best! We have the best feature set! 100% of the Fortune 100 use our products—what do we need SVVP for?”

Relax, I understand where you’re coming from. But, honestly, let’s get real about this. VMware, do you want to remove the #1 obstacle to customers adopting your technology? That #1 obstacle is support, and whether you like it or not the introduction of the SVVP by Microsoft gives you a vehicle whereby you can remove that obstacle. A refusal to participate in the SVVP—even if you disagree with the program in principle—merely locks VMware out of many opportunities where Microsoft will be able to walk right in. That’s right! Your superior technology is going to lose out to technology that is just “good enough” simply because of support. Is that what you want?

So go sign up for SVVP now. If you don’t, you’re giving the competition a great big weapon to use against you. The power to remove that weapon is yours.

UPDATE: Looks like I waited a bit too long to chide VMware on their lack of inclusion in SVVP. In any case, I’m glad to see the news. Good job, VMware! (My thanks to Dave, who pointed this out to me.)

I’m not really sure where or when it started, but over the last couple of years I started taking a strong preference to plain text communications. Perhaps it’s an increased amount of time spent on Usenet newsgroups (I’m still waiting for Panic to release a substantive update to Unison!), or perhaps its due to the annoyance of HTML e-mail that include more pictures than text; I don’t know. In any case, I set my e-mail client (Mac OS X’s Mail.app) to use plain text by default when composing messages, and I used the “hidden” preference to show the plain text alternative for messages when it’s available:

defaults write com.apple.mail PreferPlainText -bool TRUE

So that’s all well and good, but what I’ve noticed is that Mail.app seems to “ignore” some of the line endings in my message. It primarily only happens in signatures; I haven’t noticed it happening in the body of the message. At the same time that I adopted plain text messages, I also adopted the “standard” signature delimiter of two dashes and a space, so my signature will typically look something like this:

-- (hidden space at the end here)
Scott

What happens is that Mail.app turns it into this:

-- Scott

What in the world? Why is Mail.app playing with my signature? I’ve also noticed that in my longer signature—where I include my official title, phone numbers, company name, etc.—that Mail.app plays with the line endings there as well.

It also seems that this may be somehow related to Exchange Server 2007, as it only seems to happen to messages sent through my corporate Exchange infrastructure (I use IMAP and SMTP for connectivity to Exchange). I can’t find a single instance of an e-mail message where this has happened with any of my other non-Exchange e-mail accounts. But this doesn’t really make much sense, because the message I’m seeing is the local copy after it is submitted via SMTP. Perhaps the way in which Mail.app interacts with the SMTP server affects how the message in the Sent mailbox looks? I don’t know.

This is really irritating. If I type something, Mail.app (or Exchange Server) should NOT be going back and changing what I type. Anyone have any clue what could be going on here, or how I might fix it?

If this is indeed accurate, then this is big news. The Hypervisor recently published a comparison between VMware Workstation 6 and Hyper-V, and found that VMware Workstation 6 was faster than Hyper-V for a variety of tasks.

This is quite surprising, and I’m hoping we won’t find out that the testers installed VMware Tools for VMware Workstation but didn’t use the enlightenments for Hyper-V (or some other similar move). That would just be wrong. If you’re going to use optimizations available on one platform, you should also use optimizations on the other platform as well.

In the meantime, if anyone turns up more information on this comparison and the details behind the comparison, I’d love to hear it.

My colleague and friend, Aaron Delp, recently published a post titled Hyper-V for the ESX Engineer. It’s a good post, and provides a good overview of Hyper-V for someone who might already be familiar with VMware Infrastructure 3 (VI3). With sincere apologies to Aaron for plagiarizing his title, I thought I might add a few thoughts, comments, or clarifications to his post.

• Aaron mentions that Hyper-V is paravirtualized. Well, sort of. Hyper-V does support a paravirtualization interface (Hypercall, I believe?) for guest operating systems (i.e., Linux) that support it. In addition, future Windows guests will be “enlightened” as well. The confusing part about this is the fact that Microsoft (and Citrix, too) use the term “paravirtualization” to refer to the use of paravirtualized drivers instead of referring to the guest OS itself. Paravirtualized drivers are really nothing more than virtualization-optimized drivers, and it’s possible to use paravirtualized drivers even when the guest OS has no idea it’s being virtualized. In my mind, that’s not the same as “true” paravirtualization. Note that VMware ESX supports VMI, another paravirtualization interface, for guests (i.e., Ubuntu Linux) that support it. Also keep in mind that every major virtualization vendor offers optimized/paravirtualized drivers, including VMware, Microsoft, Citrix, Virtual Iron, and Novell.
• You’ll also see the base Windows Server 2008 (or Server Core) installation referred to as the “Parent Partition.” All I/O travels through this installation. Whereas ESX uses a direct I/O model (drivers embedded in the virtualization engine), Hyper-V uses indirect I/O (drivers residing in the parent partition). Each side thinks their approach is the best, of course.
• Aaron makes some comparisons between Quick Migration and VMotion, which is understandable but not entirely appropriate. Quick Migration is not live migration, but is really more comparable to VMware HA. Quick Migration has some advantages over VMware HA (can be configured on a per-VM basis), but also has some disadvantages (requires a dedicated LUN for each VM for which Quick Migration is enabled). I’ve discussed Quick Migration vs. Live Migration before.
• Aaron briefly mentions SCVMM and expresses some doubt regarding using SCVMM 2008 (currently in beta, due to be released Q4) to manage VI3. It’s certainly possible, and it does require VirtualCenter in order to work. Whether it’s the home run that Microsoft hopes it will be is another story.

Thanks to Aaron for providing a good overview of Hyper-V. For more information, I’ll refer readers to some of my Hyper-V and SCVMM session liveblogs from Tech-Ed back in June:

VIR367: Hyper-V Security and Best Practices
A Discussion with Jeff Woolsey
VIR253: Microsoft System Center VMM 2008, Part 1 of 2
VIR360: Microsoft System Center VMM 2008, Part 2 of 2
VIR250: Advanced Storage Connectivity for VMs
VIR358: Hyper-V Architecture, Scenarios, and Networking
VIR350: System Center VMM Advanced Integration

For even more resources, readers can also use the HyperV tag to browse the site for all articles tagged for Hyper-V.

Oh, and if you don’t have Aaron’s RSS feed in your RSS reader, you’re missing out. He’s producing some really great stuff that you need to be reading. Go subscribe now!

I ran across this handy white paper about OpenSSH on Linux using Kerberos authentication with Windows and Active Directory. There’s not a whole lot in there that isn’t also covered in my Active Directory integration notes, but it is useful information nevertheless.

I got notice of this whitepaper back during Tech-Ed but it’s been sitting in my “blog posts to write when I get time” pile until now. Microsoft has posted a whitepaper (download it here) as well as a blog entry (viewable here) regarding Windows Server 2008’s new power saving functionality.

While some of the functionality is genuinely new and useful—like the monitoring of CPU utilization and throttling of CPU speed accordingly—some of the stuff in the blog entry, at least, isn’t. Including Hyper-V virtualization as a “power saving feature” of Windows Server 2008 is a bit disingenuous, since any server virtualization solution will provide power savings simply from the simple fact of consolidating multiple workloads onto a single server.

If you’re interested in learning more about how Windows Server 2008 attempts to reduce power usage, have a look at these resources.

Sanbolic, whose Melio FS product I discussed a short while ago, announced today the availability of their Kayo file system. The official press release is here in PDF format. Quoting from the press release:

Sanbolic today announced that Windows Server 2008 Hyper-V virtual machines can now be stored on a single shared storage area network (SAN) storage volume using Sanbolic Kayo File System. The virtual machines can then be moved independently between physical host servers using Quick Migration because all host servers have shared access to the virtual machines files. Kayo FS will be price at $299 per host server and sold in a 5 license bundle.

Kayo FS is described as “VMFS for Hyper-V,” providing file level shared access to a shared SAN volume. This is distinguished from Sanbolic’s advanced file system, Melio FS, which provides byte-range locking and can provide concurrent access to application data on a SAN. The use of either Kayo FS or Melio FS resolves a key problem with Hyper-V deployments that want to take advantage of Quick Migration functionality, and that is that each VM would require its own LUN.

The introduction of Kayo FS also removes the key objection to the use of Melio FS for Hyper-V deployments: price. Kayo FS will be priced much lower than Melio FS; this means organizations adopting Hyper-V will be much more likely to swallow the cost of Kayo FS vs. Melio FS.

Yesterday, Brian Madden wrote an interesting editorial about how he thinks that Citrix will drop the Xen hypervisor in favor of Hyper-V, and will essentially “port” XenServer to run on Hyper-V. Keith Ward at Virtualization Review picked up on this in his post titled “The End of Xen?”. Today, Brian posted a follow-up article clarifying that he wasn’t talking about XenServer, but the open source Xen hypervisor.

Architecturally speaking, the commercial XenServer product and the open source Xen hypervisor are inextricably linked to each other. I don’t see how it would even be possible for Citrix to “port” XenServer, which is a Linux dom0/parent partition plus an “enhanced” build of the Xen hypervisor, to run on Windows Server 2008, or even to use Microsoft’s hypervisor. Keith addresses this point in his article:

I’m not sure what Brian’s sources are on that, but I’ve talked to people in the know for both Microsoft and Citrix, and they state that although the two hypervisors interoperate very well, that they are not duplicates, or near duplicates, of each other. They were developed entirely separately, but there is a common perception, in fact, that Hyper-V is based upon Xen. Not true.

It’s probably pertinent to clarify some architectural issues at this point. (Experts and gurus, feel free to correct me if I am wrong.) Both XenServer (and non-commercial Xen implementations) as well as Hyper-V must have the parent partition present in order to function; they cannot function alone. This is because critical functions like networking and storage are routed through the dom0/parent partition. Without dom0 (a Linux instance for XenServer and non-commercial Xen implementations) or the parent partitions (Windows Server 2008 for Hyper-V), the hypervisor has no I/O functionality. This means that Xen is very closely tied to Linux, and Hyper-V is very closely tied to Windows. Making either run with the other would be a monumental task, if it’s even possible. I could be wrong; while these two products share some architectural similarities, they still seem worlds apart to me.

So, in my mind, the idea of Citrix dropping the use of the open source Xen hypervisor—or any commercial variants of the hypervisor—in favor of Hyper-V are so far-fetched so as to be nonexistent.

Now, that’s not to say that Citrix won’t try to provide some enhanced functionality for Hyper-V, such as live migration (what they call XenMotion and what VMware calls VMotion). This is a key feature that is missing from the initial release of Hyper-V. Is this even possible, though? If it is possible, is it worthwhile? Microsoft has already publicly stated on multiple occasions that live migration will come to Hyper-V in a future release. Why spend a great deal of time, money, and development cycles adding functionality that Microsoft is planning on building anyway?

It’s also very possible, even likely, that Citrix will expand their XenDesktop offering to encompass virtual machines hosted on Hyper-V, thus combining their application/desktop delivery expertise with Microsoft’s hypervisor and virtualization management capabilities. Now that’s quite a possibility, in my opinion. This would be just another example of how Citrix has survived over the years by plugging the gaps in Microsoft’s product line, this time offering significant and beneficial desktop virtualization functionality to Hyper-V environments.

Like everyone else in the virtualization world (except for perhaps the folks in Palo Alto, CA), there’s a lot of Hyper-V stuff crossing in front of me.

This time it’s an article on storage options for Hyper-V, written by Jose Barreto. (You’ll recall that I referenced Jose’s clustering article a few days ago.) Out of the wide variety of blogs coming out of Microsoft, Jose’s is one that I have really, truly found informative and helpful. The home page for his blog is here.

Jose also wrote a follow-up article on Hyper-V’s storage options where he discussed booting from iSCSI.

Great work, Jose! Keep it coming.