On UNIX and UNIX-like systems, log files are simply text files that are continually appended, either by the server processes that they are associated with or by system-logging daemons.

In this section, we provide an overview of generic UNIX tools available on all UNIX distributions - ps, SAR and vmstat.

Be careful if you are using a UNIX or UNIX-like system other than Linux, because other operating systems provide commands called watch that are completely different.