System information

Tracing Tools 193

Tracing Tools

SUSE Linux Enterprise Server comes with a number of tools that help you obtain use-

ful information about your system. You can use the information for various purposes,

for example, to debug and find problems in your program, to discover places causing

performance drops, or to trace a running process to find out what system resources

it uses. The tools are mostly part of the installation media, otherwise you can install

them from the downloadable SUSE Software Development Kit.

NOTE: Tracing and Impact on Performance

While a running process is being monitored for system or library calls, the

performance of the process is heavily reduced. You are advised to use trac-

ing tools only for the time you need to collect the data.

17.1 Tracing System Calls with

strace

The strace command traces system calls of a process and signals received by the

process. strace can either run a new command and trace its system calls, or you can

attach strace to an already running command. Each line of the command's output

contains the system call name, followed by its arguments in parenthesis and its return

value.