Troubleshooting and performance monitoring

1. Troubleshooting and performance monitoring Unit objectives • Identify good troubleshooting practices and troubleshoot common hardware and software problems • Monitor system performance using command line and graphical utilities

2. Topic A • Topic A: Troubleshooting • Topic B: Performance monitoring

3. The maintenance cycle

4. Troubleshooting methodology • Monitoring • Examine log files • Use monitoring utilities • Proactive maintenance • Prevent problems from occurring • Reactive maintenance • Fix problems when they occur

5. Common troubleshooting procedure

6. Troubleshooting methodology: rules • Prioritize problems • According to severity • Spend a reasonable amount of time given priority • Try to solve the root of the problem • Avoid missing the underlying cause of a problem • Try to justify why a certain solution is successful

7. Exercise A-1 Discussing troubleshooting methodology

8. Hardware problems • Absence of a device driver • Prevents operating system from using hardware devices • Kudzu program • Program used to detect and install support for new hardware

9. The kudzu welcome screen

10. Configuring hardware using kudzu

11. Exercise A-2 Resolving hardware problems

12. Software problems • Dependencies • Prerequisites for program execution • shared libraries • other packages • ldd command • Displays shared libraries used by a program continued

13. Software problems, continued • ldconfig command • Updates the /etc/ld.so.conf and /etc/ld.so.cache files • /etc/ld.so.conf files • Contains a list of directories that contain shared libraries • /etc/ld.so.cache file • Contains the location of shared library files

14. File descriptorsand logs • Filehandles • Connections a program makes to files • ulimit command • Modifies process limit parameters • /var/log directory • Contains most system log files

15. Operating system problems • Most software problems are related to the operating system • Typically problems with boot loaders, filesystems, and serial devices • mkbootdisk command • Creates a boot floppy disk

16. Keywords used with the setserial utility

17. Exercise A-3 Resolving software problems

18. Activity A-4 Viewing and modifying package dependencies

19. Topic B • Topic A: Troubleshooting • Topic B: Performance monitoring

20. Performance monitoring • Hardware problems • Improper configuration • Old and failing • Jabbering • Failing hardware components send large amounts of information to the CPU continued

21. Improving software performance • Upgrade CPU • Buss Mastering • More RAM • Faster hard drive • CD-ROM on separate controller • Smaller kernel

22. sysstat utilities • System Statistics (sysstat) package • Performance monitoring utilities • mpstat, iostat, sar, and isag • Multiple Processor Statistics (mpstat) utility • Displays CPU statistics continued

23. sysstat utilities, continued • Input/Output Statistics (iostat) command • Displays Input/Output statistics for block devices • System Activity Reporter (sar) command • Displays various system statistics

24. Options to the sar command

25. Activity B-1 Using the mpstat, iostat and sar commands

26. Other performance monitoring utilities • top command • Displays memory usage, swap usage, average CPU Load • free command • Displays memory and swap statistics • vmstat command • Displays memory, CPU, and swap statistics

27. Activity B-2 Using top, free, and vmstat commands

28. Unit summary • Identified good troubleshooting practices and learned how to troubleshoot common hardware and software problems • Monitored system performance using utilities