Xen

I guess I’m a little behind the times here, but a little company named Bluebear is in the process of developing a cutting-edge cross-hypervisor management tool named Kodiak.

Kodiak is in private beta right now, so we can’t test it ourselves to see what it looks like. Based on the screenshots available on the website, and through what I’ve seen in talking with one of the developers in the #vmware channel on IRC, it’s pretty awesome. And the best feature? It’s cross-platform! Written in Adobe AIR, it runs on Windows, Linux, and (my personal favorite) Mac OS X. In addition to being cross-platform, it’s also intended to be hypervisor-neutral, managing VMware, Xen, and Hyper-V. Only VMware support is present right now, but support for the others is coming.

If Kodiak ends up being as good as it looks like it will be, this will be awesome tool. As a VM admin, you’ll want to stay on top of the development of this tool.

I recently had the honor of participating in an e-mail interview with OdinJobs regarding virtualization and how to “break into” the virtualization industry. My fellow cohorts in this e-mail interview were Bob Plankers and Martin MacLeod. The interview questions focused on things like the best way for a sysadmin to get started with virtualization, what skills may be vendor-specific or not, and where virtualization may be headed. It was pretty interesting to participate, and it’s even more interesting to see how Bob and Martin responded to the questions.

You can read the full interview here at OdinJobs.

Welcome to another installation of Virtualization Short Takes!

• For you Quicksilver lovers out there that also run VMware Fusion, here’s a handy trick to allow you to launch Windows apps to run under Fusion via Quicksilver.
• Duncan of Yellow Bricks points out this VMware Communities Forums thread discussing how to determine which host has a lock on a LUN. This thread also makes brief mention of the new VMFS version, version 3.31, that was released with ESX 3.5, which does a better job of handling SCSI reservations than previous versions. Good find, Duncan!
• Speaking of the new VMFS version, a summary of the information shared in the VMware Communities Forums threads can be found here.
• While we are on a bit of a storage kick, VMware has launched a new VMware Storage blog, and one of the early posts deals with VMFS. The post primarily attacks the notion of VMFS as a “proprietary” file system (which it is) by describing the advantages that VMFS provides. I’m hoping that the new storage blog will get more technical than marketing in the future, but the information is useful nevertheless.
• This link falls more into the “ironic” category than anything else. Do you suppose he got into trouble with Citrix for blogging about how to use a competitor’s product to test ICA performance?
• John Howard gives us an in-depth look at Hyper-V’s handling of virtual NICs in this article. This is particularly important for users who are interested in cloning VMs hosted on Hyper-V; I would assume that SCVMM 2008 will handle this correctly.
• This news emerged several weeks ago via VMblog.com. It’s good to see Leostream getting some recognition; their broker is actually quite good in many respects.
• Sven over at Virtualfuture.info recently blogged about XenServer’s HA functionality and how Marathon’s EverRun products play into that functionality. I actually had a conference call with the folks from Marathon several months ago about EverRun, but never got around to blogging about it. I do like the fact that you can control HA functionality on a per-VM basis, whereas VMware HA is applied to all VMs. (Well, I suppose you could disable HA for the VMs that you don’t want restarted, but it’s not quite the same.) I do agree with both Sven and PeterB’s comments regarding “Continuous Availability”; the sooner that VMware gets this functionality out the door, the more of a leg up they’ll have on the competition.
• As has been reported elsewhere as well, Reflex Security has released the Reflex Virtual Security Center (VSC). The full press release is here. Based on what I’ve read thus far, it appears that the idea behind the VSC is to combine the information from multiple instances of their Virtual Security Appliance (VSA) so that users get the “full view” of what’s occurring across the virtual infrastructure. In this regard, it is remarkably similar to Altor Networks’ Virtual Network Security Analyzer (VNSA), which is also designed to provide visibility across the entire virtual infrastructure.

As always, feel free to share other interesting links and news in the comments below. Thank you!

Here’s the latest installation of Virtualization Short Takes, my occasionally-weekly view on various virtualization news, reviews, and other happenings. Hopefully I can share something interesting with you!

• Via VMblog.com, I saw that Transitive Corporation is supporting the use of QuickTransit within Hyper-V virtual machines. This is interesting because it extends the ability of Hyper-V to help customers consolidate applications. QuickTransit, in case you aren’t aware, allows applications written for Solaris/SPARC environments to run in Linux/x86 environments. It was also the technology behind Apple’s Rosetta, which allowed Mac users to run PowerPC apps on Intel Macs. Does anyone know if QuickTransit is supported within VMware VMs, or is this specific to Hyper-V?
• This one was quite interesting to me. Question #2 is particularly applicable: why is a reboot required, anyway? (Yes, yes, I know—there is a workaround that does not require a reboot. It’s the principle of the matter.)
• Via various sources on the Internet, I learned about the release of ESX Manager. This looks like quite an interesting tool, although I have not yet had the opportunity to install or try it yet. Anyone out there tried this and have some feedback for us?
• Every now and then, something comes up about Citrix XenServer and Xen and it makes me wonder about the relationship between Citrix and the open source Xen community. The latest thing is what appears to be an offhand comment by Simon Crosby of Citrix where he says, “Because we own the hypervisor, we can do much more integration and development around it” (read it in context here). What does that mean? What does “ownership” of the Xen hypervisor mean? And if the Xen hypervisor is licensed under an open source license (GNU GPL v2, according to this page), how can Citrix make proprietary extensions to the hypervisor without being forced to release those extensions back to the community? I guess I just don’t understand the relationship there and how it works. This is where the murky waters of a commercial entity “owning” an open source project come into play, in my mind.
• I ran across this very useful tip for creating a vSwitch with a specific number of ports. It looks like Dwight Hubbard, the maintainer of the site, also has some other interesting posts. Might be worth adding his feed to your RSS reader.
• Nick Triantos discusses NetApp’s Site Recovery Adapter (SRA) and its role with VMware Site Recovery Manager (SRM). Anyone have any links to similar discussions of the SRAs for other storage vendors?
• John Howard provides a great breakdown of how Hyper-V generates dynamic MAC addresses and how Hyper-V attempts to protect against MAC collisions in some circumstances.
• The VI3 Security Hardening Guide has been updated, which is good because some people felt it just didn’t go far enough.
• VMware re-iterated their stance on being storage protocol agnostic, and in the article included a very useful table that summarizes the various products and technologies and which are supported with which storage protocols. While the rest of the post is helpful, that summary of supported features is probably the most helpful.
• Interesting in trying out Hyper-V, but don’t have shared storage? Take a look at this blog post. I think you’ll find it helpful.

I’m always on the lookout for other interesting or useful virtualization news, tips, and tricks, so feel free to share with me and other readers in the comments.

Here’s Virtualization Short Take #12, a collection of links I’ve gathered over the last week or so and my thoughts on them. Enjoy!

• For those that missed it in the Release Notes, VMware added support for Storage VMotion and 10Gb Ethernet with iSCSI SANs, as outlined in this VI Team blog entry. I went back and reviewed the Release Notes and didn’t see this listed anywhere, so this is news to me. Of course, I already knew that Storage VMotion worked just fine with iSCSI, but this added formal support for iSCSI.
• Virtualfuture.info published some good recommendations for running Citrix in a VI3 environment. If you run Citrix Presentation Server…er, XenApp…in a VI3 environment, these tuning tips may prove quite handy.
• VMware’s Virtual Reality blog posted an entry on some of the architectural advantages of VMware Infrastructure in comparison to the two leading competitors, Xen (any Xen-based solution) and Hyper-V. Many of the things listed as advantages by VMware are severe points of contention with the other vendors, such as the direct vs. indirect I/O model. Ultimately, time will tell which model was the best; I honestly don’t know enough about the deep dark internals to really state which is better. One thing I am glad to see pointed out is the true comparison of hypervisor sizes; Microsoft can say all they want that Hyper-V is only 600K in size and therefore is the “thinnest” hypervisor, but the truth of the matter is that Hyper-V can’t run without Windows Server 2008 in the parent partition. As a result, it doesn’t really matter how “thin” Hyper-V is, does it?
• Via Mike Laverick, I learned that Microsoft may have brought up the whole 64-bit hypervisor vs. 32-bit hypervisor argument yet again. Mike used a snippet from this Microsoft Virtualization Team Blog entry; in reading it myself, I don’t get quite the same 64-bit vs. 32-bit that Mike picked up. That’s good, because I didn’t want to have to go there again. Personally, the tone I picked up from the whole article was one of educating people far too accustomed to Virtual Server/VirtualPC and trying to educate them on how Hyper-V is different.
• Virtualization analyst Chris Wolf recently posted an entry in which he questioned if Apple would capitalize on the opportunity that virtualization is creating. It’s an interesting scenario, one that is similar to a scenario that I discussed a couple of years ago in a piece titled “Application Agnosticism.” In that article, I suggested that seamless host-guest interactions with virtualization software (now implemented by VMware as Unity and by Parallels as Coherence) would usher in a new wave of computing. I suggested that Mac OS X was ahead of the curve because of its ability to run native OS X applications, UNIX applications, X11 applications, Windows applications via WINE (or the commercial variant CrossOver Office), and applications from any other operating system via virtualization. Sounds like I may have been a bit ahead of my time!
• Chad continues discussing VMware HA with another post on some additional configuration options for HA. Also check out the comments with links to even more information on HA’s advanced configuration options.
• This VMware KB article has some good information on getting LUN identification information. The breakdown of the command-line output from esxcfg-mpath is particularly helpful (and for that reason I’ve added it to my del.icio.us bookmarks).
• Rich of VM /ETC shares with us a “Doh!” moment he had when he saw this simple method for identifying VMs with snapshots. Sometimes it’s the simplest solutions that evade us the longest. Here’s what I want to know: Aaron, what exactly does “/HEADDESK” mean, anyway?
• This article at SearchNetworking.com brings to light some of the challenges networking professionals face with server virtualization. I do agree with one point made in the article regarding the mapping of applications—what the end users really care about—to the networking infrastructure. VMware’s support for CDP in recent versions of VMware Infrastructure is a step in the right direction, but there is still more work to do for sure. I’m not so sure about the rest of the points in the article, but I may be an exception to the norm; I was a CCNA for a while (on track for CCNP) and have done my fair share of Cisco configurations, so I’m no stranger to the networking world. The use of VLANs to ease configuration in a server virtualization environment seems just second nature to me. Also, I did note that the author indicated that “server administrators sometimes inappropriately configure the switches to create a loop” (referring to vSwitches in ESX). How exactly does that happen? I’ve never seen a way to link two vSwitches together without using a VM.

As always, readers’ thoughts are welcome in the comments!

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.

Here in Virtualization Short Take #11, I offer to you a collection of virtualization-related news and tidbits and my thoughts on them.

• I seem to be on a bit of kick reading Ryan Arneson’s stuff these days. This time is actually an older post of Ryan’s on using the COMSTAR stuff from Sun with ESX. It’s an interesting read. I’m quite fascinated by the myriad things that Sun is doing with storage, and I hope that some of these actually get backed with good execution. I’ve guess I’ve heard the saying “Sun is where storage goes to die” from too many Sun veterans.
• I was notified of this post by Chris Barclay of Virtual Iron regarding a comparison of Virtual Iron Virtualization Manager and Citrix XenCenter. This is an interesting comparison considering that both products are built on the same underlying hypervisor (Xen). In this case, Chris makes the argument that management is the piece that sets one virtualization solution apart from other solutions, and that in this particular case Virtual Iron’s management capabilities far exceeds those provided by XenCenter. I don’t have any direct experience with either of these products, so I can’t attest as to the accuracy of his claims. While I don’t necessarily agree that the hypervisor is being commoditized, I do agree that management is increasingly becoming the factor that distinguishes solutions. In this regard Microsoft has an early lead, in my opinion, with cross-platform VM management inside Virtual Machine Manager 2008. Will other vendors follow suit?
• Last week the new VMware Networking blog posted a notice about a new whitepaper jointly authored by VMware and Cisco. Duncan over at Yellow Bricks also picked this up, but from a different source; the whitepaper, however, appears to be the same from both sources. I haven’t had the opportunity to fully review it yet, but I do plan to do so and will highlight any notable recommendations here.
• Chad Sakac, the “VMware Guru” for EMC, published an entry on stretched ESX clusters. This article was picked up by a number of other bloggers (here or here, for example), so I won’t rehash it all here again. The timing on the article was helpful; he wrote that and not more than two days later I had a customer asking about doing this very thing. Personally, I agree with Chad that it’s generally a bad idea, and so it was handy to be able to point the customer to this article as further support. One other thing I did get out of Chad’s post—how many of you picked up that up to 10 different isolation addresses can be configured? Is that in the documentation somewhere and I just missed it?
• Continuing on with Chad, it appears that an old VMware HA article of mine is useful in helping to understand how the VMware HA admittance algorithm works. Chad’s article provides excellent details on the key concepts to understand.
• Most readers have probably seen the article describing how to access the ESXi command line. This article also shows you how to enable SSH access to that CLI. I found this information so handy that I added it to my del.icio.us bookmarks. As ESXi gains broader adoption, this kind of stuff will be very useful.
• With the release of Hyper-V, comparisons of Hyper-V vs. ESX will become much, much more common. Here’s another one for review as well. I’ll echo the comments in this article regarding the comparisons: it’s not about the brand, or the technology, it’s about the solution.
• I’ll have to partially disagree with the sentiment behind this article regarding the use of virtualization as a DR tool. The article intends to present 5 things that should be considered when using virtualization for DR, but does not, IMHO, accurately present some of the challenges around virtualization for DR. How are the VMs being replicated over to the DR site? Replication technologies need to be properly coordinated with the virtualization software so that the data being replicated is consistent and useable. If this is synchronous replication it’s not as much of an issue, but it’s definitely an issue with asynchronous replication. What about registering VMs on the DR site? How does one handle VirtualCenter in this kind of scenario? Is testing failover really that easy? My experience indicates that while virtualization can certainly assist in creating a good DR plan, it’s only one part of an overall DR solution, and it can create its own unique challenges. Again, the timing of this is interesting; I just came across the article after finishing up a presentation about the use of virtualization in disaster recovery solutions.
• Anyone working in the VDI environment has almost certainly had more than their fair share of discussions about remote display protocols. This article on x86virtualization.com provides a decent overview of VNC, RDP, ICA, and Net2Display. Seems like I recall seeing something somewhere about VMware assisting in the development of Net2Display; anyone know anything more about that?

I guess that about does it for this round. Thanks for reading, and feel free to share your thoughts in the comments.

I had the opportunity today to spend a few minutes in a one-on-one conversation with Jeff Woolsey, Senior Program Manager for Hyper-V at Microsoft. During our conversation, Jeff and I discussed the Hyper-V architecture, comparisons to other virtualization solutions, and some common competitive arguments for or against Hyper-V. I’d like to publish a summarized version of our conversation here. (Jeff, if you’re reading and I’ve accidentally misquoted you, please be sure to correct me. I don’t want to misrepresent any information. Keep me straight!)

I framed the discussion around a series of questions. Each question is listed below, along with a summary of the discussion resulting from that question.

Question 1: What are the key architectural advantages of Hyper-V as compared to Xen or ESX?

Jeff indicated that Hyper-V and Xen are architecturally very similar. Both use a privileged VM; Microsoft calls it the parent partition, Xen calls it dom0. In both cases, I/O is routed through this privileged partition and only the privileged partition has access to the physical hardware. Microsoft believes the hypervisor should be as thin as possible; Hyper-V is only about 600K worth of code. The networking stack and the storage stack are pushed up into the parent partition to keep drivers out of the hypervisor. Jeff referred me back to his session earlier in the day, where he discussed the need for the parent partition (my summary of that session is here). ESX puts all the drivers in the hypervisor, which means that they have a harder time providing support for new hardware (the example given was 4Gbps Fibre Channel HBAs vs. 8Gbps Fibre Channel HBAs). In talking about the placement of device drivers, our discussion naturally led us to the next question.

Question 2: How would you respond to the concerns about the quality of the device drivers in the parent partition affecting the stability of the hypervisor?

Jeff doesn’t buy into this argument. Unlike desktops or workstations, administrators don’t typically go willy-nilly with drivers on production servers. Drivers are generally provided by the hardware vendors. In addition, because Hyper-V requires the x64 edition of Windows Server 2008, this is even less of an issue; it’s impossible to use unsigned drivers with x64 Windows. This means that any driver that can be used with Hyper-V will be WHQL-tested. Supposedly, this will keep out potentially faulty device drivers. Jeff pointed to the exclusive use of Hyper-V to power the MSDN and TechNet web sites at Microsoft as proof. I can see his point, but I still have to wonder if another level of qualification and validation shouldn’t have been established to ensure that everything works as expected with Hyper-V. It still seems possible to me that organizations stepping outside the “Big 3″ server vendors—Dell, HP, and IBM—could run into issues.

Question 3: How much interoperability is there between Hyper-V and Citrix XenServer?

Jeff admitted that this was outside his comfort area. I was specifically wondering about a Citrix claim of the ability to take a XenServer VM, move it to Hyper-V, and boot it right up. Jeff couldn’t confirm if that was possible. He did indicate that there would be a hypercall adapter that would support paravirtualized Linux kernels designed to run under the Xen hypervisor as well as non-PV Linux kernels. As for interoperability of Integration Components (ICs) or paravirtualized drivers, Jeff wasn’t sure. I should get more information on that soon and will post it here as soon as I receive it.

Question 4: What is your response to complaints about Microsoft’s support policy for third-party virtualization solutions?

This discussion really got Jeff animated. He pointed me to an announcement that I apparently missed from this morning’s keynote regarding the Server Virtualization Validation Program. This was mentioned in the official press release, but I really don’t recall seeing or hearing anything about it this morning. More information and more links about the SVVP, as I like to call it, is found in this Windows Server Division Weblog post. The idea behind the program is providing a framework to enable third-party virtualization solutions to qualify and validate running Windows Server 2008 on their hypervisor as well as providing a process for handling technical support cases, transferring cases between vendors, escalating cases, etc. Jeff tried to compare the idea of the Server Virtualization Validation Program to WHQL, which I can kind of see, but that analogy only goes so far. Without this program, I can certainly see Jeff’s points regarding the complexity of who will be supported, what versions will be supported, how they will handle patches to the supported versions, etc. With this program, other virtualization vendors have a clearly defined process they can follow to get the same support as Hyper-V (or close to it).

In my mind, Microsoft must strike a very delicate balance here. Lots of people—competitors, partners, customers, resellers—see Microsoft’s behavior here as anti-competitive, even if that isn’t the case. Again, I can certainly see the complexities involved; it just seems like Microsoft perhaps should have moved more quickly to address this issue.

Question 5: How would you address competitors’ complaints about how Hyper-V requires a separate LUN for each VM for which Quick Migration functionality is needed?

Jeff admitted that it is true that Hyper-V will require a separate LUN for each VM that needs Quick Migration functionality. Rather than spending time creating a clustered file system, Microsoft chose instead to allow storage partners to create those solutions. He referred me to Sanbolic, whose MelioFS clustered file system and LaScala volume manager will allow Hyper-V deployments to store multiple VMs on a single LUN visible to all hosts, just like VMFS. According to Jeff, this allows organizations to use both, if they so desire, instead of being “locked in.” Using a third-party clustered file system eliminates the “one VM per LUN” limitation imposed when using Quick Migration.

In my opinion, relying on partners to fill certain portions of the solution is certainly a valid approach. Lots of companies do this. In this situation, though, it seems a bit odd. For other areas of their virtualization solution, Microsoft likes to tout the completeness of the solution. Consider the tight integration of the various System Center components with Windows Server 2008 and Hyper-V. But for this they want to rely on a partner? I have to wonder if a clustered file system developed by Microsoft isn’t somewhere on the road map.

And that was the end of our discussion. I’d like to thank Jeff for taking the time to talk with me, answering my questions, and sharing his thoughts on these topics.

I came across an interesting paper discussing how various virtualization environments protect well-behaved VMs from misbehaving VMs. The paper is available here.

In the tests described in the paper, researchers used virtual machines on Xen 3.0 (the open source hypervisor not the commercial XenServer product, as far as I can tell), VMware Workstation 5.5, and “Open Solaris 10” (quotes mine). As pointed out in the paper, these three environments represent paravirtualization, full virtualization, and OS virtualization (or containers). I’m not sure if the researchers actually meant OpenSolaris; I suspect not since that’s a very recent release. Instead, I believe they probably just meant Solaris 10. On Xen and VMware Workstation, both running under Linux, they used Linux-based VMs; on Solaris, they used additional instances of Solaris. Each VM or instance ran Apache 2 and was tested using physical clients to connect to the HTTP server in each VM.

The results are interesting; VMware showed the best protection of well-behaved VMs from a misbehaving VM, followed by Xen with Solaris Containers providing the least protection. The level of protection was tested using a memory consumption stress test, a CPU stress test, a disk I/O stress test, and a network I/O stress test. I’d encourage you to have a look at the full paper for all the details.

These results are very interesting, but I wonder how much the results would change if we were to use VMware’s ESX server product line instead of one of the hosted products like VMware Workstation? As a product representative of “full virtualization” solutions, I’d be curious to know if the results seen with VMware Workstation were also seen with ESX.

In any case, the results are a validation of what we, as consultants, have been talking about: full virtualization provides the best isolation of well-behaved workloads from ill-behaved workloads, preventing a workload in one VM from affecting other workloads due to mishandling of CPU, RAM, disk, or network resources. As the researchers conclude in the paper, “…it is clear that VMware completely protects the well-behaved VMs under all stress tests. Its performance is sometimes substantially lower for the misbehaving VM, but in a commercial hosting environment this would be exactly the right tradeoff to make.”

Here are some virtualization links I found interesting over the last few days:

• Duncan points out a VMTN thread regarding VMware HA behaviors in “heterogeneous” clusters, i.e., clusters that include 1/2 vCPU VMs as well as 4 vCPU VMs. The recommendation is to move these 4 vCPU VMs into their own cluster to help address this issue. This is similar to the discussions I had here about VMware HA failover capacity calculations, and it goes to further reinforce the fact that planning is needed to fully take advantage of VMware HA’s functionality. It’s not quite “fire and forget” just yet, folks.
• Via a number of different sites, I learned that VMware has released version 2.1 of VDM. More information is available in the Release Notes. Of key interest to me is the defined process for bulk importing individual desktops, which will make it easier for organizations that already have a number of desktop images to bring those VMs into VDM.
• On the VMware performance blog, they’re discussing achieving 100K IOPS with a single ESX server. While some of the readers are taking VMware to task for what they call an “unrealistic” test, I do have to agree with commenter Chad who points out that this exercise wasn’t intended to create a “best practices” configuration. The point was simply to see just how high the IOPS could go—nothing more, nothing less, just a test to see how high they could take the number. Yes, I think we’d all agree that using a cluster without 1:1 VM-to-VMFS mappings would be a realistic test, and personally I’d love to see the results of a test like that as well. Even so, it’s still handy to see that the I/O subsystem of ESX is more than capable of handling even the most demanding workloads.
• It becomes more obvious every day that I really need to take some time to learn PowerShell. With Microsoft embedding PowerShell in all their products and VMware embracing it via the VI Toolkit, it’s becoming ubiquitous. Now VMware is even showing off a series of videos about the VI Toolkit and its functionality. Ugh..I need more hours in a day to keep up with all this stuff.
• Paul Shannon of VM-Aware points out this VMware page describing support for Microsoft products, both from Microsoft as well as from various OEMs. Useful information to have, especially when you need to reassure a concerned customer about their support options. Personally, I think it’s just poor business (or poor ethics, take your pick) for Microsoft to be giving customers a hard time about virtualization support while developing their own virtualization product. Come on, we all know that the day Hyper-V goes RTM, Microsoft will start offering full product support for virtualized instances—well, virtualized instances running on Hyper-V, anyway. Am I wrong?
• Via Ruben at Brian Madden’s site (and thanks to an e-mail from Patrick Rouse himself), I learned about this VDI broker comparison created by Patrick Rouse of Quest/Provision Networks. Right now, it only compares VDM, XenDesktop, and Provision Networks Virtual Access Suite (VAS), but they are open to including additional brokers if enough requests come in.
• Brian Madden delves into an extended discussion of the key problem with VDI solutions: the display protocol. He posits that Citrix is in better shape than VMware because of the ICA protocol, but both suffer from the same problem in that “neither ICA nor RDP can remote all applications.” It’s a good read.
• This may be a bit dated now, but here’s some information on an unattended installation of Windows Server 2008 with Hyper-V.
• InformationWeek recently published an article describing Hyper-V’s “advanced virtualization features.” The two things that are really touted by the article are I/O optimization via driver enlightenments, and support for failover clustering at the host level. Driver enlightenments, unless I am mistaken, are equivalent to Xen’s paravirtualized drivers, VMware’s VMware Tools, and Virtual Iron’s VI Tools; they all accomplish the same thing. I’m not sure how having the same feature as all the other competitors makes it “advanced”. It sounds like a standard feature if you ask me. Host clustering support is nice, but not that different from VMware HA; I believe Citrix is due to introduce a similar feature for XenServer soon as well. (It’s my understanding that Marathon Technologies plans to build their “Continuous Availability”-like product to extend this new XenServer HA functionality.) Not that I’m knocking Hyper-V or these features that are slated to be included in Hyper-V; you just can’t call them “advanced” if pretty much every other virtualization solution on the market also has the same features.

Well, that’s it for now. If you have links that you’d like to share with me or other readers, feel free to add them in the comments below or put them in my del.icio.us inbox. Thanks for reading!