The concept behind the ClearCube PC blade solution is very compelling: take PCs off end user desks and lock them away in a secure, manageable environment, such as a corporate datacentre. Moreover, it’s not that difficult to do using ClearCube PC blades and client terminals, although exactly how you go about it does take a little explaining. ClearCube's PC blade solutions cost from around £600 per user, depending on the architecture, number of blades and clients chosen.
So let’s start with the easy bit, the hardware, where -- just like blade servers -- each ClearCube PC blade is in fact a self-contained computer designed to be plugged into a special rack-mounted chassis. Two types of blade are available: one has a Pentium 4 processor (the R1200), while the other (the R2100, also known as the 'fatboy') can accommodate a pair of Xeons. Up to 2GB of memory can be configured on the R1200 and 4GB on the R2100, and both blades feature on-board nVidia Quadro4 graphics controllers capable of handling multiple monitors. Just as with a standalone PC, there’s a choice of hard disk and operating system -- typically, a flavour of either Windows or Linux.
The ClearCube chassis into which the blades are plugged is similarly straightforward. A modular affair, it’s based on a 3U cage unit able to take eight single-processor blades or four of the dual Xeon products. Up to 14 cages can be fitted into a 42U rack and managed as a single array; each has its own hot-swap fan tray and dual power supplies, for extra reliability, plus an individual modular BackPack unit containing the interfaces required to connect the blades to their remote users.
In fact, the BackPack fulfils two roles. One is to provide the external Ethernet interfaces and a switch needed to connect the blades to the company network; the other is to connect each blade to the remote user terminals -- something that can be done in one of two ways.
The most functional, and also the quickest in terms of perceived performance, is to use ClearCube’s own C/Port technology. Here the analogue video signals are squirted down ordinary UTP wiring or, using converters, fibre cables. At the other end, custom C/Port terminals are fan-free, solid-state devices, with connectors for the local screen, keyboard and mouse, along with speakers if required and, optionally, local USB devices. Multiple monitors can be supported, and C/Port users can be located up to 200 metres away from the racks of ClearCube blades.
Alternatively, it’s possible to connect to the blades over an ordinary Ethernet network using industry-standard thin client terminal technology. To this end, ClearCube sells what it calls I/Port terminals, based on NeoWare thin-client hardware, with a choice of either Linux or XP Embedded models. Again these are solid-state devices with no fans or other moving parts, making them almost silent in operation. However, any Microsoft RDP (Remote Desktop Protocol) compatible solution can be used instead, including software-based clients running on other devices.
Whatever you choose to use, it all works very well indeed -- and from the user perspective, there's no real difference between a ClearCube PC blade and a standard desktop system. Apart, of course, from having the bulk of the hardware located elsewhere and no noisy fan or hard disk to interfere with phone calls and other conversations.
Performance using the C/Port terminals, in particular, matches what you’d get from the equivalent standalone system with no delays in screen refreshes even in a multi-terminal setup. Failover to a preconfigured spare blade is almost instant, there’s support for high-resolution displays and you can run more or less any software that would normally be hosted on a desktop PC.
Unfortunately the I/Ports aren’t quite as impressive and failover is much less seamless; even so, performance is good and on a par with what you would get from an equivalent one-to-one thin client setup. A dedicated network helps, as the thin client traffic can then be separated from general LAN data, while for light use ClearCube supplies WinConnect XP software to allow up to four clients to be hosted on a single blade.
On the management front, a complete suite of tools is available (ClearCube Management Suite 4.0) with graphical consoles to monitor blade status, configure hot spares and remote control end-user desktops. Administrators can also identify blades to engineering staff by flashing on-board LEDs and scrolling massages across a small LCD panel built into the blade hardware.
Using the CMS software, C/Port users can be assigned to any available PC blade in the same chassis and hot spares configured in case of a hardware failure. With the I/Ports, however, there are even more options, thanks to a unique application called Grid Center.
This client/server tool is used to manage the thin client I/Port connections, and has the ability to not only connect any user to any blade in the entire rack, but also dynamically allocate users to predefined blade pools. It can even track usage and direct users to the most under-utilised blades when they log on, while power users are directed to reserved systems. Plus, there are facilities to automatically hot-swap users when blades fail and centrally manage updates to drivers and software on the I/Port terminals.
Finally, yet more functionality can be added through the use of virtualisation software, such as VMWare, making it possible to further share out processing capabilities yet still manage client allocation using Grid Center. Indeed, ClearCube has recently announced an agreement with IBM, which is to add Grid Center management to its VHCI (Virtualised Hosted Client Infrastructure) based on IBM’s BladeCenter hardware plus VMWare software and Citrix thin clients.