A Study of Introduction of the Virtualization Technology into Operator Consoles

We introduce a virtualization technology into the control system as operator consoles. The virtualization technology is a hot topic for server computing. The virtualization technology enables to consolidate a lot of server computers to a few host computers and reduces system maintenance cost drastically. Recently a dozen of commercial and non-commercial virtualization products are proposed. We evaluated several virtualization products on the point of view on performance. The response time of the network communication between distributed computers on MADOCA control framework was measured. We selected Xen as a virtualization environment, since it has enough performance and a function of high availability. We discuss requirements of future computer for virtualization environments and showed a practical side of introducing the virtualization technology into beamline control system as operator consoles. INTRODUCTION Virtualization technologies have gotten a lot of attention recently to simplify management of computers. A proliferation of computers leads to an increasing of unwanted maintenance tasks. Virtualization technologies can consolidate many existing computers onto fewer servers. By introducing a server virtualization we can reduce computers and its maintenance costs. In SPring-8, about 50 beamlines are operating. Each beamline has at least a front-end VMEbus system and workstation as an operator console. The workstation is set on each beamline that is located around the storage ring with 1.5 kilometers circumference. The maintenance on distributed computers is not easy. In the case of a certain computer failure, the downtime of the control system on a beamline might need about one hour. And we must keep complete independency of computing environment between beamlines. The server virtualization is better way to solve them. Virtualization technologies are not novel technology. It is originated from the mainframe [1, 2], which was able to run many virtual machines (VMs). Each VM has an independent computer resource separated real hardware and can run an individual operating system instance. In this decade, the performance of modern computers advanced rapidly and they have become inexpensive. The distributed computing of large amount of computers became a main technique by speeding up the network. However, the frequency of the trouble increases in proportion to the number of the computer although the reliability of the recent computer became high. An explosive increase in the number of computers pushed up the total cost including the management cost in recent years. The virtualization technology has revived as a method of breaking such a situation. We can now obtain virtualization environment on a general-purpose server computer. This gives lowering frequency of machine failures and reduction of total cost. In this paper, we described the introduction of the virtualization technology as operator consoles, and showed possibilities of a real no-stop control system. VIRTUALIZATION TECHNOLOGIES There is various approach to implement the virtualization from a proprietary product to open sources. Figure 1 shows some typical structures of virtualization. One is based on hardware emulation as shown in figure 1-(a). CPU, Disks and Network interface card (NIC) are emulated by the software layer. VMware and VirtualPC [6] are corresponding to this category. QEMU [7], Bochs [8] and Plex86 [9] known as open source products emulated the instruction set of x86 architecture completely. The overhead is extremely large, they cannot be used practically. However, this approach has a merit that the original operating system of Windows, Solaris, Linux, etc. can run without any modifications. 10th ICALEPCS Int. Conf. on Accelerator & Large Expt. Physics Control Systems. Geneva, 10 14 Oct 2005, TH1.3-8O (2005)