LAS VEGAS--The Day One keynotes at Citrix Synergy 2009 were about users and desktops. Today was nominally about data centers and clouds--of which there were a variety of announcements. However, Citrix's XenClient ("Project Independence") loomed large as well.
Of the products discussed on stage, XenClient is perhaps furthest from being a fully realized product. But is also offers an intriguing window into how the PC as we know it is likely to fundamentally change over the coming years.
XenClient is a "Type 1" native hypervisor that sits on a PC and hosts one or more guest operating systems. This approach contrasts with the "Type 2" hosted hypervisors that are far more common on PCs today.
There are good reasons why we tend to see native hypervisors on servers and hosted hypervisors on desktops. Native hypervisors are higher performance, especially when it comes to interacting with networks and disks. As a result, it wasn't until native hypervisors like VMware ESX Server and Xen came to market that x86 virtualization started to seriously move beyond useful but relatively narrow uses such as in test and development labs.
The downside of native hypervisors is that, because they sit directly on top of a system's hardware, they have to take over a variety of the functions that an operating system usually performs. For example, a native hypervisor has to deal with things like power management and needs to know how to talk to graphics cards and chips, network and storage adapters, and other system hardware.
(Depending upon the virtualization architecture in question, some device interactions can be passed through to the guest operating systems, but the point remains that a native hypervisor is exposed to hardware details and idiosyncrasies that are masked if the hypervisor is hosted on an operating system.)
The great diversity of client hardware relative to server hardware therefore makes running native hypervisors on a PC tricky business.
It's also been the case that vendors haven't exactly pushed client-side virtualization--in contrast to using application virtualization to deliver software to clients--in a broad way. Hosted virtualization products handle specific use cases such as security (VMware ACE), running Windows applications on Macs (Parallels Desktop for Mac, VMware Fusion), and software development (VirtualBox, VMware Workstation). Start-ups are also tackling the security angle with alternative approaches. RingCube uses containers. Neocleus uses a Xen-based native hypervisor.
But no large vendor has seriously pushed a broad-based Type 1 hypervisor for the client. Microsoft, for its part, has been publicly skeptical about the idea. (Not especially surprising given that Microsoft has only reluctantly embraced virtualization--in part because native virtualization takes over some of the traditional tasks of the operating system.)
That changes with XenClient, a project that Citrix has collaborated on closely with Intel.
Here's how Citrix describes XenClient and its vision for desktop computing:
XenClient is a strategic product initiative with partners like Intel, focused on local virtual desktops. We are working together to deliver on our combined vision for the future of desktop computing.
This new virtualization solution will extend the benefits of hosted desktop virtualization to millions of mobile workers with the introduction of a new client-side bare metal hypervisor that runs directly on each end user's laptop or PC. This together with an innovative back-end desktop management solution for creating, delivering, and updating corporate desktop computing environments will transform the way corporate desktops are delivered and managed, giving IT all the security, simplicity and cost savings of centralized management, with an unprecedented level of performance, personalization and freedom for end users.
To net it out, Citrix is pushing for a future in which a hypervisor is a standard abstraction layer for every cleint and server--just the way that x86 architectures of all stripes are architected and built. Think of it as a BIOS on steroids if you will.
Citrix's interest here is obvious. After all, its strategy is to make money from managing virtualized environments. Thus, continuing with a theme from Synergy's first day, XenClient--like XenServer--will be free when made available later this year.
Intel's interest here is that XenClient is specifically targeted for systems with vPro technology. vPro includes:
- Intel Virtualization Technology (VT)--hardware assists for improved virtualization performance
- Intel Trusted Execution Technology (TXT)--formerly called LaGrande, provides hardware-based rooted security
- Intel Active Management Technology (AMT)--hardware management technology
Intel's Pat Gelsinger said in his keynote that vPro is ramping quickly--he claimed it was in 60 percent of the Fortune 100--but Intel is doubtless actively seeking more reasons to get businesses to upgrade to their latest and greatest client platforms.
The vision here seems a sound one. After all, IT vendors have essentially been adding layers of abstraction to mask complexity since the beginning. Even an operating system is an example of abstraction (actually many of them rolled into one software package). And use cases involving personal PCs used to access corporate networks or protected VMs that run security scanners seem far less esoteric than they did even just a couple of years back.
The question is more one of time frame. When do compelling uses get made available by software vendors in largely transparent ways for end users who are not developers or otherwise ready, willing, and able to explicitly manipulate multiple virtual machines on a single client? It isn't this year but there's a lot of reason to believe that this is the direction the client is headed.
LAS VEGAS--The consumerization of the Web will be as disruptive to distributed computing as distributed computing was to the mainframe. That was the central theme of Citrix Systems CEO Mark Templeton's keynote speech at this week's Synergy 2009 conference.
Mark Templeton, CEO, Citrix Systems
(Credit: Citrix)This is an oversimplification, of course. Over the years, companies have run their business software in many different ways--not all of which are easily categorized as either mainframe-like or PC-like. One whole era of computing architectures during roughly the 1980s commonly went by the term "client-server." However, if we think of how distributed computing in the enterprise has evolved, this broad-brush statement makes a lot of sense.
That's because the enterprise PC isn't really a personal computer any longer. The administrative and security requirements around desktop and notebook devices running an increasingly complex stew of locally installed software have seen to that. In many enterprises, they're stringently locked down as a way to protect their often fragile software payloads from corruption.
This is a drum that virtualization and cloud-computing specialist Citrix has been pounding for quite a while. Writing after Citrix iForum (Synergy's predecessor) in November 2007, I noted:
We've seen and heard a lot of praise for the democratic impulse associated with this particular phase of computing that often goes by the Web 2.0 moniker. Anyone can post. Anyone can publish. Anyone can photograph. Your vote matters in social media.
And alternative ways of accessing and running applications have indeed made it easier to do things outside of a strict IT framework. In his closing iForum keynote, Citrix CEO Mark Templeton used the phrase "making the personal computer personal again" for this idea.
It's perhaps not too surprising that the proffered solution to this problem is a variety of technologies that Citrix collectively describes as application delivery. The framework to think about it is something like a satellite TV system. A controller, a delivery network, and a receiver transmit and receive the bits; they do so independently of the actual end-point device (i.e. the TV) and the content, so long as those adhere to certain interface standards.
One could use such an architecture to deliver enterprise applications to a truly personal notebook, an employee's personal system rather than an IT asset. Although still relatively uncommon in an enterprise context when it comes to PCs, it's a fairly common model with smartphones, though we're starting to see the beginnings of such an approach in the PC space too.
What this means specifically in a Citrix environment is that Citrix Delivery Center "head-end controllers" such as XenApp and XenDesktop advertise services--that is, applications that are available for users to run. New services or service updates are then loaded or streamed to a client.
One of Tuesday's major announcements was Citrix Receiver, which the company describes as "the first universal client for IT service delivery":
Under the hood, Citrix Receiver is a lightweight universal software client with an extensible browser-like "plug-in" architecture. Receiver comes standard with a variety of optional plug-ins that communicate with head-end infrastructure in the Citrix Delivery Center product family such as XenApp, XenDesktop, Citrix Access Gateway, and Branch Repeater.
These plug-ins support functionality such as online and offline app usage, virtual-desktop delivery, secure access control, password management, app acceleration, multimedia acceleration, service-level monitoring, and voice communications. This model enables IT to effectively operate as a service provider to their own employees, proactively and transparently monitoring end-user experience from a central location.
Receiver is available for Windows, Macs, and iPhones. Citrix also plans to support Windows Mobile and Symbian operating systems. It's also working with Open Kernel Labs to support Android. In all cases, Receiver is free.
In general, as with XenServer, Citrix' strategy is to make its money from the management and delivery software infrastructure rather than all of the base-level components.
The final announcement of the day was Dazzle. It's built on top of Receiver and accesses the same head-end services. It is, in a sense, Citrix application delivery meets Web 2.0.
I mean that in a somewhat metaphorical sense. But Dazzle is a self-service application store for employees that very deliberately and consciously mimics the conventions and approach of something like the iTunes Store. Web 2.0 and cloud-computing attributes, like self-service, device independence, and remote access are what help so many consumer applications make traditional enterprise apps look a bit shopworn by comparison.
And that's what Mark Templeton was talking about when he said the enterprise application delivery model is being disrupted by the consumer Web.
I noted last month that embedding the code for server virtualization directly into the hardware, something called an embedded hypervisor, hasn't taken off to any significant degree.
Rather, most IT shops continue to purchase virtualization as a third-party add-on (typically from VMware or Citrix), or they acquire it as part of Linux distribution or Microsoft Windows.
Many of the management and other services associated with virtualization are going to be added on, in any case. However, the thinking of a lot of people went, wouldn't it make sense to at least get the foundation in place as part of the server purchase, given that we're seeing more and more interoperability between the various hypervisors and the software that exploits them?
Since writing that piece, I've received a variety of interesting comments, and had some discussions with IT vendors and others I thought worth sharing.
Reader rcadona 2k commented:
Adopting a hypervisor is an active choice or, in most cases, a surrender of your hardware. Embedded hypervisors aren't just a BIOS; they require formatting your storage a particular way (VMware VMFS, Hyper-V NTFS, LVM/raw LUNs for Xen). The virtual BIOS features amongst hypervisors for the guests are not standardized, and the virtualized guest devices are not standardized. When you pick a Type-1 hypervisor, you lock yourself into another "platform."
Some good points here. We have a a bad habit in the IT industry of using the word "commodity" when we really mean things along the lines of "widely used with variants available from multiple sources" (and, therefore, relatively low-price). Hypervisors are an example of this. They all do roughly the same thing. There are a variety of suppliers. And the price for base-level hypervisors has been sliding toward zero.
But they're not commodities. For all the interoperability work that has been taking place at the management and services layer, there remain significant product differences that affect things as substantial as an IT shop's storage architecture. Some of these will go away--or at least be abstracted away--over time, but not all necessarily will.
Given that the choice of hypervisor still matters in such important ways, it's understandable that people continue to buy them primarily as an explicit component of the broader virtualization software ecosystem that depends on them.
Another feedback theme was just that we're still in the early days of virtualization. Perhaps most notably, when VMware rearchitected ESX Server to create the embedded ESXi version, not all the capabilities and features carried over. (Without going into all the details, the full ESX uses a Linux-based service console to manage the hypervisor; ESXi does away with this and is much thinner as a result. However, the current iteration of ESXi doesn't fully replicate all the capabilities provided by that console.)
However, the VMware partners that I've spoken with fully expect that upcoming ESXi versions will soon reach parity with the older ESX architecture and that this will therefore cease to be a reason to shy away from the embedded approach.
I remain skeptical that embedded, just-built-in hypervisors are going to become the norm that it once seemed they would be. If nothing else, Microsoft's Hyper-V--most likely predominantly installed as part of Windows--will tend to hold sway in Microsoft-centric environments, of which there are many.
At the same time, it's too early to write off the idea of embedding hypervisors just because the idea hasn't gained a lot of initial momentum.
Here's the basic question: where does the hypervisor--the software layer that underpins server virtualization--live and who owns it? Is it just part of the server or is it just part of the operating system?
For now, to be sure, it's often something that IT shops purchase from a third-party--we're mostly talking from VMware here. However, pretty much everyone expects that over time this foundational component will be increasingly built-in--even if the higher-level value-add management and virtualization services that make use of it are explicitly purchased from a variety of sources.
Virtualization vendors have often considered this an important question.
A few years back, I had written a piece about how Novell and Red Hat were adding the Xen hypervisor to their Linux distributions. And that Microsoft had made clear its intention to add virtualization to Windows--technology now known as Hyper-V. In short, virtualization was starting to move into the operating systems of a number of vendors.
Well, that notion didn't sit well with Diane Greene--then CEO of VMware--as she made clear to me by coming over and grabbing me by the lapels(only somewhat figuratively) at an Intel Developers Forum event. From Diane's, admittedly biased, perspective the hypervisor should be independent of any single operating system. I hadn't said otherwise. But I apparently didn't make the opposing case enthusiastically enough.
At the time, VMware ESX Server (its native hypervisor) had to be installed as with any other third-party software product. However, over time, VMware and other virtualization vendors came out with versions of their products that could be installed from a USB memory stick or other form of flash memory. It was called ESXi in VMware's case.
Thus the embedded, or at least embeddable, hypervisor was born with rumors throughout 2007 becoming product announcements in September of that year.
There's actually a lot to be said for the embedded hypervisor. Lots of IT environments--especially enterprise ones--do indeed have a mix of operating systems and operating system versions. Given that, there is indeed a lot to be said for the idea that hypervisors just come with the server as a sort of superset to the firmaware, like BIOS, already loaded on every system. Then IT administrators could just configure any guest OSs they want on top.
It's logical. But it's not really playing out that way--at least so far.
After all the initial excitement in late 2007, embedded hypervisors didn't really go anywhere in 2008. Instead, Microsoft's Hyper-V rolled out and KVM found its way into the main Linux kernel as an alternative style of Linux virtualization backed by Red Hat.
Whether or not it makes "sense," in some theoretical, architectural sense, it's no longer clear to me that embedded hypervisors are going to be the path that the industry predominantly follows.
Rather, at the moment, homogeneous environments are tending towards whatever is built into the OS. And enterprises are going to their ISV of choice--sometimes Citrix for XenServer--but far more often VMware for ESX.
At the very least, it now looks as if--for the foreseeable future--IT shops will acquire virtualization, including hypervisors, in a variety of ways that vary as a function of their individual requirements, circumstances, and vendor alignments.
Analyst Brian Madden identifies desktop virtualization as a major 2008 virtualization theme:
If you could sum up the year with a single theme, that theme would be "desktop virtualization is here to stay." I don't want to go so far as to say that desktop virtualization is mainstream, but 2008 saw Microsoft, VMware, and Symantec getting serious about it, and Citrix fighting to keep the lead (it'd) established via XenApp over the past decade.
I concur.
"Desktop virtualization" isn't a single thing; it's really a shorthand for a variety of approaches, the common thread of which is that they're not traditional Wintel "fat clients." And it dovetails with other technology approaches--such as rich Internet applications (RIA) and browser-based application access--that are only virtualization in the most conceptual sense.
I started seeing a swelling interest in alternative ways of delivering applications and software services to a variety of clients in 2007. But I agree with Madden that the trend accelerated in 2008, albeit at a measured pace often driven by security and compliance concerns more than return-on-investment arguments.
2008 saw Citrix rationalize its entire virtualization portfolio around the Xen nomenclature--breaking from its successful but narrow Presentation Server roots. And VMware's View announcement in December filled out a client-side portfolio that had been missing some major pieces previously.
Microsoft, meanwhile, rolled out Hyper-V and announced a new version of its application virtualization product. And systems vendors such as Dell, Hewlett-Packard, IBM, NEC, and Sun Microsystems also expanded or updated their offerings on the desktop side.
The desktop, as we've come to know it, has hardly gone away. New devices that depend on applications running in the network and data stored there tend to supplement, rather than replace, more traditional clients.
But some of our applications now usually reside in the network; we tend to regard an unconnected PC as a crippled thing. And that opens up a frame of mind that will move more and more "state" (whether applications, personal data, or other services) off local devices and into either corporate data centers or the cloud.
When I put together an overview of VMware's virtualization portfolio in May of this year, my focus--like the company's--was on their products that establish a virtualized infrastructure, and then manage and automate virtual-machine life cycles on top of that infrastructure.
It's not that VMware didn't have desktop products. In fact, its first product, still popular among developers, was VMware Workstation. And in practice, it has the default back-end server virtualization used for virtual desktop infrastructure installations. I went on to write that:
For many companies, this desktop portfolio would be an enviable product lineup in its own right. However, it's not at the core of VMware's strategy. VMware's primary focus is, rather, on back-end infrastructures, not the client.
This reflects, in part, where the most interesting use cases lie and, not incidentally, where there's the most money to be made. It's also a function of where computing is headed--into the data center and into the cloud.
VMware was clearly doing work behind the scenes to amp up its presence in virtualization related to clients. However, it remained a work in progress and largely out of the limelight--more a set of point products and solutions than a systematic capability.
That's now largely changed. With its VMware View announcement on December 2, the company now has both a fairly complete set of client-side virtualization products and a more structured approach to organizing the portfolio.
Before getting into what VMware View is, it's worth noting what it is not. It's not an umbrella for all VMware work related to clients. Thus, products such as VMware Workstation, VMware Fusion (desktop virtualization for the Mac), and VMware ACE (which extends corporate resources to unmanaged PCs) remain an independent set of products for now.
That said, an experimental "offline desktop" capability that VMware announced as part of View dovetails with virtualization on the desktop (using a new client hypervisor project still under development), so it wouldn't surprise me to see further integration over time.
Rather, View is focused on delivering virtual desktops (and applications) hosted on back-end virtual infrastructure to client devices. VMware describes View as a renaming of Virtual Desktop Infrastructure (VDI), though it also rolls in both other existing products and new ones. In addition to the aforementioned "offline desktop," View covers three primary areas:
VDI: This is a combination of VMware Infrastructure--that is, the software services running in the data center to create and manage the virtual machines that are being delivered to the desktop--and View Manager. Manager is the renamed Virtual Desktop Manager, the "connection broker" tool that handles tasks such as connecting the right client to the right virtual machine.
Application virtualization: ThinApp is the result of VMware's acquisition of Thinstall in January 2008. It can be thought of as a complement to VDI. Whereas VDI delivers a complete operating-system image (along with all its applications) to a client device, application virtualization delivers a specific application to a client, whether virtual or physical.
Storage optimization: View Composer is a new product that uses "Linked Clone" technology to create virtual desktops and propagate updates from a single master. One of the reasons that this type of software is important in VDI installations is that typical desktop images contain many of the same files. VMware estimates that Composer will typically reduce storage requirements by about 70 percent.
Overall, VMware remains more server-centric than client-centric. In a sense, it's a mirror image of Citrix in this regard, reflecting differences of historical focus. Prior to acquiring XenSource, Citrix was solely about delivering applications to clients (as was its close partner, Microsoft).
VMware, on the other hand, really made it big by enabling companies to consolidate servers and thereby reduce the number of physical boxes they had to buy. However, there's an ever-increasing interest within IT shops in moving away from traditional approaches to deploying and managing desktops. So, if you're a serious virtualization player--and VMware's the biggest such--you pretty much have to make a serious client play.
And VMware is doing so.
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