Troubleshooting any operating system can involve a whole suite of specialized software. However, sometimes you just need a quick tool to report specific aspects of your computer. Table A.11 contains some of these utilities found in Linux environments.
Table A.11. Common Troubleshooting Tools
| COMMAND | GENERAL USAGE | DESCRIPTION |
|---|
| dmesg | dmesg | Displays the kernel ring buffer. |
| free | free | Displays the amount of free and used memory on the system. |
| hwinfo | hwinfo | Queries and displays detected hardware. |
| iostat | iostat [OPTIONS] INTERVAL COUNT | Displays CPU statistics and input/ output statistics on block devices (hard disks). Common options include -d
Print device utilization -t
Print time for each report -x
Print extended statistics |
| lsof | lsof [OPTIONS] | Lists currently open files. Common options include -b
Find open files on the specified filesystem mount point |
| ltrace | ltrace [OPTIONS] COMMAND | Traces library calls made by a process. Common options include -c
Count time and calls, and return a summary upon completion -p
Used to attach to a running process |
| sitar | sitar | Comprehensive reporting tool used to generate a report documenting the entire running environment. The report file can be located in the /tmp/sitar-<SERVER-NAME> directory. |
| strace | strace [OPTIONS] COMMAND | Traces system calls and signals made by a process. Common options include -c
Count time and calls, and return a summary upon completion -p
Used to attach to a running process |
| uname | uname [OPTIONS] | Displays kernel version information. |
| vmstat | vmstat | Displays virtual memory statistics. |