2.5.4. The Sysstat Suite of Resource Monitoring Tools
- Displays an overview of CPU utilization, along with I/O statistics for one or more disk drives.
- Displays more in-depth CPU statistics.
- Known as the system activity data collector,
sadccollects system resource utilization information and writes it to a file.
- Producing reports from the files created by
sarreports can be generated interactively or written to a file for more intensive analysis.
iostatcommand at its most basic provides an overview of CPU and disk I/O statistics:
Linux 2.4.20-1.19184.108.40.206.10.ent (pigdog.example.com) 07/11/2003 avg-cpu: %user %nice %sys %idle 6.11 2.56 2.15 89.18 Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn dev3-0 1.68 15.69 22.42 31175836 44543290
iostatdisplays an overview of the system's average CPU utilization since the last reboot. The CPU utilization report includes the following percentages:
- Percentage of time spent in user mode (running applications, etc.)
- Percentage of time spent in user mode (for processes that have altered their scheduling priority using
- Percentage of time spent in kernel mode
- Percentage of time spent idle
- The device specification, displayed as
<major-number>is the device's major number, and
<sequence-number>is a sequence number starting at zero.
- The number of transfers (or I/O operations) per second.
- The number of 512-byte blocks read per second.
- The number of 512-byte blocks written per second.
- The total number of 512-byte blocks read.
- The total number of 512-byte block written.
iostat. For more information, refer to the