Computerworld

SoftGrid streams app manageability

Virtualization is all the rage these days. Chances are good that if you're not pursuing some sort of application or server virtualization strategy now, you probably will be in the near future; the potential cost savings are that compelling.

However, not all virtualization technologies are made the same. In fact the term virtualization has gradually expanded in scope during the past few years, now encompassing everything from classic virtual-machine monitors, such as VMware and Microsoft Virtual Server, to sophisticated virtualized application-deployment solutions.

Softricity's SoftGrid falls under the latter category. A Windows-based software virtualization platform, SoftGrid lets IT shops effectively eliminate one of the most challenging aspects to managing Windows applications: deployment and maintenance of the installed base. By dissecting and repackaging an application's installation image -- a process Softricity calls "sequencing" -- SoftGrid makes it possible to deliver the application to a Windows client without actually modifying the local file system or registry.

To accomplish this, SoftGrid intercepts application I/O calls and redirects them to a locally cached version in its virtual file system. In this regard, it is quite similar to Altiris SVS (Software Virtualization Solution), a product I reviewed earlier this year. However, whereas SVS is machine-specific, deploying a virtualized application to a specific client system, SoftGrid is focused on the user's log-in credentials. Applications follow the user from machine to machine, with all user settings and preferences preserved and reproduced independently of log-in location.

Another significant difference compared with SVS, SoftGrid uses streaming to deliver the virtualized code. When a user first launches the application, it delivers only certain portions of its code base -- those byte streams defined in the primary "feature block" when the application was sequenced. Subsequent use of the application runs entirely from the local cache until a previously uncached portion of the code base is requested, at which time the streaming process continues.

By contrast, SVS requires the entire virtualized application package to be delivered before it can be activated. SoftGrid can also run in this mode, a feature the company calls pre-caching, used primarily for mobile and/or occasionally connected users.

The advantage to streaming is that it allows for the aforementioned machine-independence. By tightly coupling its deployment model to AD (Active Directory), Softricity is capable of leveraging much of the roaming user profile functionality that debuted with Windows 2000. In fact, outside of the virtualization component, SoftGrid is essentially a natural evolution of the IntelliMirror technology, which forms the basis for Microsoft's current application management architecture.

Maintaining such close proximity to the Microsoft way can be a double-edged sword, however. For starters, it makes it difficult to use Softricity in a non-AD environment. You need at least a basic level of AD functionality -- a domain with DNS, for example, properly configured -- just to install the server components.

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SoftGrid's close Microsoft ties also carry over to the product's usability. I installed SoftGrid 4.0 in a VMware environment and found the user interface to be Spartan, yet functional. Softricity chose a straight Microsoft Management Console implementation, and though I've never been a fan of MMC, I was eventually able to figure out which nodes or objects hid the feature or function I was seeking. Note to Softricity: A Web-accessible version of the console would be a welcome addition.

UI issues aside, I was impressed by the overall seamlessness of the deployment model. Applications appeared when and where expected, following my test user account as I moved across both physical desktops and virtual machines.

The application sequencing process, although efficient, performed inconsistently in my testing. For example, sequencing two common applications -- Adobe Acrobat and Microsoft Office 2003 -- went smoothly: I loaded the Sequencer application, answered a few default questions, and then allowed it to "record" the changes made to the system as I stepped through the setup process for each program. I then deployed the applications by publishing them through the SMC and then refreshing the application list at each client.

I ran into trouble, however, when I attempted to install a Windows service via SoftGrid, in this case the Tracker Agent from DMS Clarity Suite. The sequencing process ran without incident. But during the "test launch" phase I discovered a key limitation of the SoftGrid virtualization model: the need for a user "trigger" -- a desktop short cut or an entry in the user log-in script -- to initialize the virtualization environment and start the application.

As are many Windows services, Tracker is designed to load at system boot under the LocalSystem account. As such, it has no real UI -- just an external applet to start/stop its service process. In the end, I was able to work around this limitation by tying the initialization of the virtual environment to a Start menu shortcut for the applet; however, this arrangement still doesn't allow the service to run prior to user log-in. Lack of support for "headless" operation is a critical omission, one that makes SoftGrid unsuitable for deploying and maintaining most systems management agents on the market today.

I've highlighted the above experience because it represents a real limitation of the SoftGrid model and because this same scenario worked flawlessly under Altiris' SVS product. SVS allowed the Tracker service to start at boot time with no user trigger or log-in -- a key technical advantage of the company's "layered" virtualization model.

At press time, we learned of Microsoft's intent to purchase Softricity and to integrate its SoftGrid technology into future Microsoft virtualization solutions. This is good news for SoftGrid fans and virtually guarantees that the product's sequencing and streaming mechanisms will be around for some time.

Overall, Softricity SoftGrid 4.0 is an interesting solution with some rough edges and limitations that will probably be softened or eliminated as the underlying technology is absorbed into the larger Windows management framework.

Bottom line

SoftGrid's compatibility quirks mar an otherwise innovative solution to the Windows app management puzzle. The underlying sequencing and streaming technology shows promise, but a reliance on user actions to trigger the virtual environment makes it unsuitable for "headless" agents and services. IT shops considering SoftGrid should also evaluate Altiris' SVS. Finally, Microsoft's decision to acquire Softricity ensures that elements of SoftGrid's deployment model will eventually become an integral part of the larger Microsoft Server System.

Cost: $US200 per CAL (client access license); $125 for Terminal Server-only CAL; $100 for SMS-deployed CAL. Platforms: Requires Windows Server 2003; supports Windows 2000, Windows XP, Windows Server 2003, and Terminal Server.