Swap space is used to supplement the use of physical memory when a running process requires more resources than are currently available. This chapter describes how to monitor the use of swap space as well as how to add more when necessary and how to delete additional swap space if it is no longer required. Swap space can be allocated either as a dedicated disk slice or in an existing file system as a normal file. The latter option is often only used as an emergency solution. Both of these methods for adding swap space are described in this chapter.
Core files are produced when a process encounters an unexpected error. When this happens, the memory contents of the process are dumped to a file for further analysis. This chapter describes the configuration of core files and how they can be managed effectively. This chapter also describes crash dump files and how to manage and configure them. Crash dump files are produced when a system encounters a failure that it cannot recover from. The contents of kernel memory is dumped to a temporary location (normally the swap device) before the system reboots and is moved to a permanent location to save it from being overwritten.
Network File System (NFS) is a means of sharing file systems across the network. NFS allows multiple systems to make use of the same physical file system without having to maintain numerous copies of the data, which could cause consistency problems. NFS is discussed in this chapter, as is AutoFS, a method of automatically mounting file systems on demand and unmounting them when a specified amount of time has elapsed during which no activity has occurred. This chapter describes how to configure automount maps and make use of this extremely useful feature.