The last time we met we explored three basic tools to monitor the server status. Now it's time to look at several more advanced tools.
The vmstat tool is used to periodically display information about the number of running and blocked processes, the internal memory status, paging, input/output operations, number of switching and interrupts, and CPU usage. This tool is not a standard part of the core system (most distributions contain it in the basic installation, however) and is included in the procps package.
The vmstat monitoring tool reads information from the corresponding v / proc files. Two values can be used as parameters. The first defines the delay between each listing and the second defines the overall number of listings. You can enter them after the -n switch:
The first column (r) contains the number of processes ready to run; the second one (b) contains the number of blocked processes. The swpd column contains information about swap usage, memory usage, swap content analysis and additional information about disk and CPU usage.
The iostat tool is used to monitor input and output device activity.
Linux 3.2.0-49-generic (gnu.cz) 21.7.2013 _x86_64_(3 CPU)
The utility output is transparent. The first line contains information about the system (core version, platform), the next one contains information about CPU usage and the last one displays file system usage/activity.
Both vmstat and iostat are more advanced but quite essential tools with which to manage a GNU/Linux server. We’ll get back to other monitoring tools later.
Author: Jirka Dvořák