Sun whips its Sun Ray thin client into better shape

Sun Ray platform makes strides in Unix-based computing

In its infancy, Sun’s Sun Ray was a network-clobbering, sometimes stuttering example of what thin-client computing on Unix-like systems could be. Now it’s much more stable and much, much thinner.

The Sun Ray thin-client computing platform is actually a combination of hardware and software. At the hardware end, there are two new clients available. The modest Sun Ray 2 offers 10/100 Ethernet, sound, and USB support. The Sun Ray 2FS is larger but adds 100FX support for greater security at the transport level, as well as the ability to run dual monitors. Both clients are outfitted with SmartCard readers to support two-factor authentication.

On the software end, the clients require the Sun Ray Software package. This includes all the server-side components that deliver a desktop to the client devices. A rather rudimentary Web management UI that can display connected clients, users, and SmartCard information is also included.

In the lab, I set up a Sun V20 Server running Solaris 10 for Sparc, and two Sun Ray 2FS clients, each with a single 20-inch LCD monitor. The network between the server and the Sun Ray clients was a dedicated 100Mbps segment, with another NIC on the server linked to the overall lab network. With the server running, powering on a Sun Ray client would bring up a Solaris Desktop log-in quite quickly, and from there, the experience was more or less like working on a local system, including stereo sound and USB device support.

Hot Desking is one of the major features the Sun Ray provides, and it works very well. In the middle of a user session, removing the SmartCard from the front of the client will revert the client back to a log-in window. Placing the card into another client will bring up a log-in window, and with a valid password, the user’s entire session appears exactly as it was on the original client. This is similar to session disconnects on Windows Terminal Services or Citrix but with the additional security measure and ease provided by the SmartCard.

Furthermore, the Sun Ray clients are truly stateless devices. Whereas some thin clients come with an embedded OS, such as XP Embedded, Sun Ray clients have no onboard OS, but rather very simple firmware that can connect to a remote server. Thus, they require no significant management and will pull new firmware versions when prompted by the server during their boot process. The Sun Ray Software also permits deploying Sun Ray servers in a fail-over scenario with both servers present on the dedicated network. The Web-based management UI is nothing to write home about, but it does give a reasonable picture of the client status and overall system availability.

Next, I built an RHEL (Red Hat Enterprise Linux) 3 x86 server on a VMware ESX 3 server instance running on an IBM System x3550 server. After linking the virtual network interfaces to the two physical NICs in the server and building the Sun Ray client network as a dedicated segment, I installed the Sun Ray Software for Linux on the server. The installation was quick and relatively painless, as was running the brief network configuration script. After rebooting the server, the Sun Ray kernel modules loaded, and the Sun Ray clients booted to a RHEL 3 log-in screen. This time, however, I put both monitors on a single Sun Ray 2FS client. After restarting the Sun Ray services on the server, the client booted with both panels active for a 3,200x1,200 desktop.

Sun boasts that the bandwidth utilization required by each client is approximately 300Kbps down and 128Kbps up. These numbers seem slightly low, but not terribly so. With the dual-monitor configuration, the downstream bandwidth numbers are roughly double that of a single-monitor client. All network traffic to and from the clients is UDP-based, and my measurements showed that at 768Kbps down and 128Kbps up, the dual-monitor client was barely usable: There were many screen artifacts when dragging windows, and sound quality was truly terrible.

At slightly higher rates, these problems were drastically reduced, and at 1.5Mbps, completely gone. Testing with a single-monitor client had these rates decreasing by about 60 percent, so I wouldn’t go lower than 512Kbps downstream in a production situation. Of course, trying to squeeze native X11 through pipes that small is impossible.

To truly test the solution, I let some dust settle on my dual-Opteron workstation running Fedora Core 5 for one week, working exclusively on the Sun Ray 2FS client with dual monitors running on the RHEL3 Sun Ray server. In fact, I wrote this review in OpenOffice on a Sun Ray session. Even for a power user, it’s quite usable, with the occasional display artifact or sluggishness when dragging windows around, but largely unnoticeable.

I did experience some problems with audio support, requiring all mixer settings to be set to the maximum level to get even low-volume audio, which was quite distorted by the high gain. Sun is preparing a patch to address this issue and sent me a prerelease, which largely fixed the problem. Still, I had occasional problems with audio volume and quality following a hot desk switch.

To reach the Windows market, Sun has released the Sun Ray Connector for Windows, which essentially runs a full-screen Windows Remote Desktop client on the Sun Ray client. This approach may seem like the long way around to those with a history of Windows-based thin-client implementations, but it does work.

Support for a modern Linux distribution would be quite welcome because my biggest problem working exclusively on the Sun Ray for the week was the rather elderly base of RHEL3, although Sun plans on introducing support for RHEL4 sometime this year. I’ve had a chance to look at the beta release of the next version, and aside from a few bugs, it builds and runs on RHEL4, which is a very welcome step.

If delivering a secure, manageable Solaris or Windows desktop is the goal, the new Sun Ray solution is worth a look. The bells and whistles are not just fluff when you need to deploy dual-monitor support or have a highly secure fiber network.

InfoWorld Scorecard
Availability (20.0%)
Scalability (20.0%)
Value (10.0%)
Configuration (10.0%)
Performance (25.0%)
Management (15.0%)
Overall Score (100%)
Sun Ray 2 and Sun Ray 2FS 8.0 8.0 8.0 8.0 8.0 7.0 7.9