vmstat
Use the vmstat command to determine where the system performance problems are. vmstat reports statistics about kernel threads, virtual memory, disks, and CPU activity.
Here is the basic syntax for the vmstat command:
vmstat [delay [count]]
- delay
- The delay between updates in seconds. If no delay is specified, only one report is printed with the average values since boot.
- count
- Number of iterations. If no count is specified and delay is specified on command line, count defaults to infinity.
| Reports from vmstat | Command |
|---|---|
| Report 10 iterations with 2 seconds delay | vmstat 2 10 |
| Report every 1 second | vmstat 1 |
| Forks report: Number of forks since the last system startup | vmstat -f |
| Disk statistics | vmstat -d |
| Sum structure report: The absolute count of paging events since system initialization | vmstat -s |
| Time stamps: The -t option gives time stamps on each line of data. This is useful analyzing data | vmstat -t <interval> <count> |