sar is a good general performance monitoring tool that can output data in almost all Linux work done. sar command provided in the sysetat rpm. Used in the example sysstat version 5.0.5, which is one of the latest stable version. Version and download information, please visit the home page sysstat http://perso.wanadoo.fr/sebastien.godard/.
sar the CPU can be displayed, the run queue, the disk I / O, page (swap), memory, CPU interruption, network performance data. The most important function is to create sar data files. Every Linux system should collect data through sar cron jobs. The sar data files to provide historical performance information for system administrators. This feature is very important, it separates sar and other performance tools area. If a batch job running twice a night until the next morning will find this case (unless wake up). We need to have the ability to study 12 hours before the performance data. sar data collector provides this capability.
sar command line of popular formats:
sar [options] [-A] [-o file] t [n]
On the command line, n and t together two parameters define the number and sampling interval, the sampling interval t, the parameters must be some, n-sampling frequency is optional, the default value is 1, -o file represents the command results stored in binary format in the file, file in here is not a keyword, is the file name. options for the command-line options, many options sar command, only common options are listed below:
-A: the sum of all reports.
-u: CPU utilization
-v: process, I nodes, files, and lock table state.
-d: hard disk usage reports.
-r: memory pages and disk blocks are not used.
-g: the case of the serial I / O's.
-b: buffer usage.
-a: file read and write conditions.
-c: system call situation.
-R: the activities of the process.
-y: terminal equipment activities.
-w: system activity.