VMware had been touting client hypervisors as the best way to offer offline support, but it put development on the back burner in favor of "client mode," which appears to be the finished version of "Offline Desktop" -- the experimental feature in VMware View 4. The new client mode lets end users save a virtual machine (VM) image for offline use. That VM gets resynchronized when the user goes back online.
"Client mode" is different from a client hypervisor in that it runs an offline VM on top of the existing client operating system, whereas the bare-metal client hypervisor would replace the local OS with a VMware View-managed OS, VMware executives said.
And Citrix will offer offline support through a client hypervisor to be heavily promoted at Citrix Synergy 2010 next week in San Francisco. The annual Citrix conference is loaded up with XenClient informational sessions. The company also will offer its customers the chance to win one of eight XenClient-based laptops.
You can't live without it
Offline support is a key component that has been missing in desktop virtualization technologies because without it, end users can access their virtual desktops only while online.
"It has been a reason for resistance to VDI [virtual desktop infrastructure]," said Dave Sobel, CEO of IT consultancy Evolve Technologies in Fairfax, Va. "So now, instead of [virtual desktops] being transparent to the end user in most ways, it will be in all ways."
Whether delivered through a client hypervisor or "client mode," offline support is a critical step forward for desktop virtualization because it removes one of the "why nots" for adoption, Sobel said.
Tony Wilburn, a desktop virtualization consultant at Arlington, Va.-based Betis Group who tested View 4.5, said once his clients try the offline support feature, they won't know how they lived without it. "Once you try it, all the possible use cases start to make sense," Wilburn said.
Client mode works on any Windows-based PC or laptop without the aid of specific software or hardware such as the Intel vPro chip, which VMware's client hypervisor will require. VMware will offer client versions of offline mode for Linux and Mac operating systems, and users will also be able to access their View 4.5 virtual desktops from a range of mobile devices.
To an end user, client mode does essentially the same thing as a client hypervisor. Yet VMware has not scuttled its plans to develop one, according to Raj Mallempati, VMware's desktop and virtualization product marketing director. However, the client hypervisor is no longer a top priority, and there is no timeframe for its availability at this point, he said.
Profile management in View 4.5
Another new feature in VMware View 4.5 is profile management through integration with the RTO Software products that VMware acquired last year.
With this technology, users can create personalized settings for their virtual desktops so they get the same experience as with traditional PCs. Profile software abstracts user profile data and stores it on a centrally managed server, so when an end user logs on, his personal settings are delivered automatically.
VMware View users have always had to buy third-party profile management software and manage it separately. Wilburn said the new profile management feature in View will be particularly useful for companies moving to Windows 7.
"Managing Windows profiles -- especially roaming profiles -- has always been difficult," Wilburn said. "By removing the profile from the registry and virtualizing it so that you get the same profile from any device without affecting the registry, VMware made things a lot simpler for View customers."
For instance, using View 4.5 with VMware vSphere and an Intel Nehalem-based server host, IT pros can put up to 20 knowledge-worker virtual desktops per server core or more for the average task worker, Mallempati said. VMware claimed View 4 scalability of up to 16 virtual desktops per CPU core.
Though View 4.5 will include more features, it will cost the same as the previous version; the Enterprise Edition is $150 per concurrent user, and Premier Edition is priced at $250 per concurrent user. The company will also extend its trade-up program to encourage Citrix XenApp customers to move to View 4.5 Premier Edition, Mallempati said.
VMware View 4.5 general availability was initially set for July. Without giving a reason, the company said last week that it would push off its release date until sometime later in 2010.