PCs come full circle
Virtual desktop software is the latest spin on server-based PC computing
- By Larry Stevens
- Sep 29, 2007
If desktop virtualization technology takes hold in office computing as many experts predict, the relationship between desktop computers and the data center will have traveled full circle. The powerful and largely autonomous PCs that sit on every workers desk could become dinosaurs.
In their place would be a no-frills terminal device that does not consist of much more than a keyboard and display. Most hardware resources and software programs would be centralized on servers in a secure data center. It would be the host-based mainframe and dumb terminal model reborn for a generation frustrated by a costly and unruly model of office computing.
A lot of work remains before office computing comes full circle. A handful of vendors offer several virtual desktop approaches, but the technology is still in its infancy.
Anyone who has looked at virtual desktops can rattle off seven or eight advantages: greater control, better security, lower cost of ownership, less power consumption, enforced compliance with organization policies, said Michael Rose, associate research analyst of client virtualization software at IDC. But the technology is new, he added. Best practices have not been developed. Price points will probably drop, and hardware to support it is only now being announced.
What we have now [in virtual desktop technology] is a 1980s BMW. Its a great car, but not nearly as good as a 2007 model. The industry should reach that goal within one to three years. Michael Rose, IDC
Nevertheless, IDC estimates that the market for virtual desktop wares, also sometimes called desktop or application streaming, will grow to $1.7 billion in the next four years.
Rose and others say now is a good time for information technology executives to become familiar with the virtual desktop model because chances are they will soon have to make some decisions about whether to use it, and if so, to what extent.
The goal of virtual desktop vendors is to make the technology transparent to users, who will still get to use their favorite programs and operating systems as before. But the lions share of the processing and the data and storage behind the virtual PC are located on a server in a data center.Improved security
One server can host multiple virtual PCs. A virtual PCs screen image is sent to a users desktop machine, which can be a full-blown PC, a thin client or even an older, obsolete PC repurposed as a thin client. The virtual desktop application on the server monitors the users mouse clicks and keystrokes and refreshes the screen accordingly.
The virtual desktop model appears to have some similarities to two other alternatives to traditional desktop computing: blade PCs and terminal services. But there are important differences.
Blade PCs involve taking a traditional PCs processor, memory and hard drive and then putting them on a card called a blade and mounting numerous blades in a rack in a data center. However, a blade PC is simply a PC removed from a desktop and installed in a data center. A virtual desktop is a centralized model in which one server in the data center typically hosts multiple PCs.
Terminal services, sometimes called server-based computing, provide users access to desktop software applications that run on a centralized server in the data center. Citrix Systems and Microsoft offer products that provide this kind of functionality. This shared model can be efficient and can work well where a common desktop environment is used by multiple employees doing similar jobs. But it isnt practical for groups that need unique and personalized desktop environments for each user, said Wes Wasson, vice president of worldwide marketing at Citrix.
The new crop of virtual desktop solutions is different because it allows for more software customization and specialized configuration of individual user desktops than terminal services. Citrix already offers some of those capabilities with its new Desktop Server line and plans to enhance them once it incorporates technology it recently acquired from XenSource, a server and desktop virtualization vendor.
One of the primary advantages IT managers hope to achieve with virtual desktops is improved security and compliance.
Those are the goals of David Siles, chief technology officer of Kane County, Ill. Siles is no stranger to virtualization technology. Since 2005, he has used server virtualization, in which multiple virtual servers run on a single physical server, to consolidate data on fewer servers and improve his shops disaster-recovery capabilities.
Now Siles is in the middle of a desktop virtualization project. By the end of this year, he hopes to be at the halfway mark toward reaching his goal of moving about 1,500 users, or 75 percent of the countys knowledge workers, to VMWares virtual desktop products, most of them running on thin clients.
Siles sees the project as primarily a security upgrade. Weve already had a number of scares when we lost laptops, he said. No personal or confidential data was ever lost as a result, but the ensuing investigation was agonizing and time-consuming.
Siles said virtual desktops provide better protection from such problems because the computers do not provide security.
It doesnt matter who has access to the computer, Siles said. The users authentication is what allows the user to gain access to applications and data.
Most county users will access their virtual PCs via new thin clients, but some will continue using laptops or traditional PCs and connect to the network from home offices or hotel rooms.
Siles said he was attracted by the manageability of virtual desktops. He must support employees spread throughout a 524-square-mile county. Fixing an employees PC sometimes involved a four-hour road trip. Now Siles manages the virtual desktops centrally from servers in the data center. He can also be certain that each desktop has the right software patches and is free of any unauthorized programs that might cause conflicts with the operating system or other applications.
Basically, everyone gets a clean computer every morning when they log on, Siles said.
Officials at California State University at San Marcos also discovered virtual desktop technology as a way to keep a tighter grip on the desktop environment.
Our professors and students think of the PCs in the computing labs like kitchen sinks, but with no disposal, said William Washburn, an operations analyst at the university. They throw everything in it, but nothing ever comes out.
For example, some users would install different versions of the same program, even though doing so makes the PC prone to crash.
To prevent that behavior, Washburn has installed Symantecs Altiris Software Virtualization Solution on 1,000 computers in the universitys labs. Users see icons on their desktop for all the software, even the multiple versions of the same application. For example, users who want an earlier version of a particular data analysis application can click on its icon, and the application is delivered to them completely partitioned from other versions.Costs, other considerations
Virtualization experts say better security and lower costs through reduced support requirements are the major initial benefits of desktop virtualization. Some also hope for eventual hardware savings, although they say those savings might not accrue for several years.
For example, Siles said Kane County pays $600 each for the thin clients it uses as virtual PCs, which is about what it would pay for a traditional PC. But the savings accrue in three or four years, he said. A PCs life cycle is three to four years, after which it breaks down or is not sufficiently powerful or upgradeable to run new versions of the operating system or applications. Because processing power and storage are not issues with thin clients, Siles expects their life cycle to be seven to 10 years, which would significantly lower the total cost of ownership.
However, one caveat is that adopters must take into account increased costs in the data center that might offset some of the PC savings. There is the cost of the servers that host the virtual desktop PC software. There is also a cost associated with centralized shared storage, such as devices configured as a storage-area network (SAN).
When you move from cheap, local storage to a SAN, with all its networking requirements, youre adding not only more dollars to the project but also a lot of complexity, Rose said. Many organizations that would do well with a desktop virtualization project arent ready to implement a SAN.
Rose said that in the next year or two, centralized storage developed specifically for thin-client, virtual desktop solutions will probably emerge.
Managers should also expect to face some potentially tricky integration and software licensing issues with the virtual desktop model, at least in the near term, virtualization experts say.
Most virtual desktop products are still not plug and play, often requiring managers to patch together different vendors products, Wasson added.
Another potential stumbling block is user acceptance of the technology, Wasson said. If you take away someones PC and replace it with a thin client, youre going to get some skepticism about how well it will work, he said. You have to prove pretty quickly that the skepticism is not well-founded.
Users primary concern typically is performance. Theres no getting around the fact that performance will vary depending on a number of factors, said Jerry Chen, senior director of enterprise desktop platforms and solutions at VMWare.Convincing users
Siles tested his virtual desktop technology to see if it would be transparent to users. He set up 18 workstations, half with regular desktop PCs and half with virtual desktop PCs. Users worked on one platform for a week and then switched to the other for another week.
In almost all cases, they reported that their experience was exactly the same on both platforms. In the one case in which the user was able to determine which type of machine she was on, it was because of an unexpected benefit of a virtual desktop PC. The power in the lab went off for a few seconds. When it came back on, the user had assumed her machine would have to reboot. Instead, the application screen she was working on before the outage occurred reappeared as soon as her display turned back on.
Virtualization experts advise officials to be selective about which users switch to virtual desktop PCs. For employees who never work outside the office, virtual desktops might be a good fit because a network connection to the server is almost always available. But employees who are accustomed to finishing projects on airplanes, in airports or vacation cottages and do not have consistent broadband access would not be the best candidates.
Rose said the virtual desktop model must overcome many drawbacks before it reaches the ambitious market figures that IDC projects for it, but he is optimistic that it will.
What we have now [in virtual desktop] is a 1980s BMW, he said. Its a great car, but not nearly as good as a 2007 model. The industry should reach that goal in one to three years.Stevens is a freelance journalist who has written about information technology since 1982.