The Linux trace command is strace. On Solaris, the command is truss. See your operating system documentation for its corresponding tracing command. When you issue the appropriate command for your operating system, the tracing immediately begins to spew forth output and continues until the process ends or you break out of the trace.

Figure 2-6 shows an Oracle Database 10g Release 1 server process operating system trace. The Oracle server process oracleprod3 has the process ID 14558. This is an active process, so many of lines in Figure 2-6 have been removed. Where the lines were removed, an ellipsis (...) was inserted.

Figure 2-6. Oracle's instrumentation through an operating system lens. Oracle has submitted a multiblock IO read request to the operating system by issuing the operating system readv call. The call took 0.6 ms, which is wonderfully fast.