Getting Started Guide 157 When the system has been shutdown and is ready to be powered off, you may see your computer rebooting, or you see this message on the screen: System halted SMP Symmetrical Multi-Processing is a capability that allows Linux (and many other operating systems) to utilize multiple CPUs on the same computer system. For example, if you have a dual-Pentium computer, Linux can utilize both Pentium chips to make your programs run faster. Previous versions of Linux did not usually have SMP enabled because it did not add greatly to the system performance. The Linux 2.2 kernel is now fully-SMP capable. This feature can be tuned if you intend to use high-performance, multi- processor systems. Swap partition A swap partition is an area of your hard disk that is set aside for the Linux kernel to use as virtual memory (see virtual memory). The swap partition is defined as part of your hard disk during Linux installation, and activated each time you boot your Linux system. Because the swap partition is used by the Linux kernel to store active programs as they run, you can’t access the swap partition directly. None of the space on that partition can be used to store normal programs or data files. The swap partition should be at least 16 MB in size. A standard metric is to make the swap partition equal to twice your system memory, but the maximum size of the swap partition is 127 MB. (You can have multiple swap partitions if you want more than 127 MB of swap space.) You can review which partition is used as a swap partition by checking the /etc/ fstab file. NOTE: Some Linux systems provide the option to use a swap file rather than a swap partition. Because a swap file is part of the normal Linux filesystem rather than a dedicated disk partition, it gives poorer performance. Using a swap file is not provided as an option when installing OpenLinux.