Command Line Tools to Monitor Linux Performance
Command Line Tools to Monitor Linux Performance
Here, we are going to see some of the Command Line Tools to Monitor Linux Performance
1. Top – Linux Process Monitoring
Linux Top command is a performance monitoring program which is used frequently by many system administrators to monitor Linux performance and it is available under many Linux/Unix like operating systems. The top command used to dipslay all the running and active real-time processes in ordered list and updates it regularly. It display CPU usage, Memory usage, Swap Memory, Cache Size, Buffer Size, Process PID, User, Commands and much more. It also shows high memory and cpu utilization of a running processess. The top command is much userful for system administrator to monitor and take correct action when required. Let’s see top command in action.
2. VmStat – Virtual Memory Statistics
Linux VmStat command used to display statistics of virtual memory, kernerl threads, disks, system processes, I/O blocks, interrupts, CPU activity and much more. By default vmstat command is not available under Linux systems you need to install a package called sysstat that includes a vmstat program. The common usage of command format is.
# vmstat procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu----- r b swpd free inact active si so bi bo in cs us sy id wa st 1 0 0 810420 97380 70628 0 0 115 4 89 79 1 6 90 3 0
3. Lsof – List Open Files
Lsof command used in many Linux/Unix like system that is used to display list of all the open files and the processes. The open files included are disk files, network sockets, pipes, devices and processes. One of the main reason for using this command is when a disk cannot be unmounted and displays the error that files are being used or opened. With this commmand you can easily identify which files are in use. The most common format for this command is.
# lsof COMMAND PID USER FD TYPE DEVICE SIZE NODE NAME init 1 root cwd DIR 104,2 4096 2 / init 1 root rtd DIR 104,2 4096 2 / init 1 root txt REG 104,2 38652 17710339 /sbin/init init 1 root mem REG 104,2 129900 196453 /lib/ld-2.5.so init 1 root mem REG 104,2 1693812 196454 /lib/libc-2.5.so init 1 root mem REG 104,2 20668 196479 /lib/libdl-2.5.so init 1 root mem REG 104,2 245376 196419 /lib/libsepol.so.1 init 1 root mem REG 104,2 93508 196431 /lib/libselinux.so.1 init 1 root 10u FIFO 0,17 953 /dev/initctl
4. Tcpdump – Network Packet Analyzer
Tcpdump one of the most widely used command-line network packet analyzer or packets sniffer program that is used capture or filter TCP/IP packets that received or transferred on a specific interface over a network. It also provides a option to save captured packages in a file for later analysis. tcpdump is almost available in all major Linux distributions.
# tcpdump -i eth0 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes 22:08:59.617628 IP webhostingchennai.co.in.ssh > 126.96.36.199.static-webhostingchennai.co.in.28472: P 2532133365:2532133481(116) ack 3561562349 win 9648 22:09:07.653466 IP webhostingchennai.co.in.ssh > 188.8.131.52.static-webhostingchennai.co.in.28472: P 116:232(116) ack 1 win 9648
5. Netstat – Network Statistics
Netstat is a command line tool for monitoring incoming and outgoing network packets statistics as well as interface statistics. It is very useful tool for every system administrator to monitor network performance and troubleshoot network related problems.
# netstat -a | more Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 *:mysql *:* LISTEN tcp 0 0 *:sunrpc *:* LISTEN tcp 0 0 *:realm-rusd *:* LISTEN tcp 0 0 *:ftp *:* LISTEN tcp 0 0 localhost.localdomain:ipp *:* LISTEN tcp 0 0 localhost.localdomain:smtp *:* LISTEN tcp 0 0 localhost.localdomain:smtp localhost.localdomain:42709 TIME_WAIT tcp 0 0 localhost.localdomain:smtp localhost.localdomain:42710 TIME_WAIT tcp 0 0 *:http *:* LISTEN tcp 0 0 *:ssh *:* LISTEN tcp 0 0 *:https *:* LISTEN
6. Htop – Linux Process Monitoring
Htop is a much advanced interactive and real time Linux process monitoring tool. This is much similar to Linux top command but it has some rich features like user friendly interface to manage process, shortcut keys, vertical and horizontal view of the processes and much more. Htop is a third party tool and doesn’t included in Linux systems, you need to install it using YUM package manager tool. For more information on installation read our article below.
Iotop is also much similar to top command and Htop program, but it has accounting function to monitor and display real time Disk I/O and processes. This tool is much useful for finding the exact process and high used disk read/writes of the processes.
8. Iostat – Input/Output Statistics
IoStat is simple tool that will collect and show system input and output storage device statistics. This tool is often used to trace storage device performance issues including devices, local disks, remote disks such as NFS.
# iostat Linux 2.6.18-238.9.1.el5 (webhostingchennai.co.in) 07/16/2018 avg-cpu: %user %nice %system %iowait %steal %idle 2.60 3.65 1.04 4.29 0.00 88.42 Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn cciss/c0d0 17.79 545.80 256.52 855159769 401914750 cciss/c0d0p1 0.00 0.00 0.00 5459 3518 cciss/c0d0p2 16.45 533.97 245.18 836631746 384153384 cciss/c0d0p3 0.63 5.58 3.97 8737650 6215544 cciss/c0d0p4 0.00 0.00 0.00 8 0 cciss/c0d0p5 0.63 3.79 5.03 5936778 7882528 cciss/c0d0p6 0.08 2.46 2.34 3847771 3659776
9. Psacct or Acct – Monitor User Activity
psacct or acct tools are very useful for monitoring each users activity on the system. Both daemons runs in the background and keeps a close watch on the overall activity of each user on the system and also what resources are being consumed by them.
These tools are very useful for system administrators to track each users activity like what they are doing, what commands they issued, how much resources are used by them, how long they are active on the system etc.
10. Monit – Linux Process and Services Monitoring
Monit is a free open source and web based process supervision utility that automatically monitors and managers system processes, programs, files, directories, permissions, checksums and filesystems.
It monitors services like Apache, MySQL, Mail, FTP, ProFTP, Nginx, SSH and so on. The system status can be viewed from the command line or using it own web interface.
rpm -ivh https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
yum -y install monit
(1/2): epel/x86_64/updateinfo | 927 kB 00:00:03 (2/2): epel/x86_64/primary | 3.5 MB 00:00:08 epel 12611/12611 Resolving Dependencies --> Running transaction check ---> Package monit.x86_64 0:5.25.1-1.el7 will be installed --> Finished Dependency Resolution Dependencies Resolved =============================================================== Package Arch Version Repository Size =============================================================== Installing: monit x86_64 5.25.1-1.el7 epel 318 k Transaction Summary ================================================================ Install 1 Package Total download size: 318 k Installed size: 818 k Downloading packages: monit-5.25.1-1.el7.x86_64.rpm | 318 kB 00:00:01 Running transaction check Running transaction test Transaction test succeeded Running transaction Installing : monit-5.25.1-1.el7.x86_64 1/1 Verifying : monit-5.25.1-1.el7.x86_64 1/1 Installed:
Installing web interface of Monit refer here
11. NetHogs – Monitor Per Process Network Bandwidth
NetHogs is an open source nice small program (similar to Linux top command) that keeps a tab on each process network activity on your system. It also keeps a track of real time network traffic bandwidth used by each program or application.
yum -y install nethogs
Resolving Dependencies --> Running transaction check ---> Package nethogs.x86_64 0:0.8.5-1.el7 will be installed --> Finished Dependency Resolution Dependencies Resolved =================================================================== Package Arch Version Repository Size =================================================================== Installing: nethogs x86_64 0.8.5-1.el7 epel 38 k Transaction Summary =================================================================== Downloading packages: nethogs-0.8.5-1.el7.x86_64.rpm | 38 kB 00:00:00 Running transaction check Running transaction test Transaction test succeeded Running transaction Installing : nethogs-0.8.5-1.el7.x86_64 1/1 Verifying : nethogs-0.8.5-1.el7.x86_64 1/1 Installed: nethogs.x86_64 0:0.8.5-1.el7
12. iftop – Network Bandwidth Monitoring
iftop is another terminal-based free open source system monitoring utility that displays a frequently updated list of network bandwidth utilization (source and destination hosts) that passing through the network interface on your system. iftop is considered for network usage, what ‘top‘ does for CPU usage. iftop is a ‘top‘ family tool that monitor a selected interface and displays a current bandwidth usage between two hosts.
13. Monitorix – System and Network Monitoring
Monitorix is a free lightweight utility that is designed to run and monitor system and network resources as many as possible in Linux/Unix servers. It has a built in HTTP web server that regularly collects system and network information and display them in graphs. It Monitors system load average and usage, memory allocation, disk driver health, system services, network ports, mail statistics (Sendmail, Postfix, Dovecot, etc), MySQL statistics and many more. It designed to monitor overall system performance and helps in detecting failures, bottlenecks, abnormal activities etc.
14. Arpwatch – Ethernet Activity Monitor
Arpwatch is a kind of program that is designed to monitor Address Resolution (MAC and IP address changes) of Ethernet network traffic on a Linux network. It continuously keeps watch on Ethernet traffic and produces a log of IP and MAC address pair changes along with a timestamps on a network. It also has a feature to send an email alerts to administrator, when a pairing added or changes. It is very useful in detecting ARP spoofing on a network.
15. VnStat PHP – Monitoring Network Bandwidth
VnStat PHP a web based frontend application for most popular networking tool called “vnstat“. VnStat PHP monitors a network traffic usage in nicely graphical mode. It displays a total IN and OUT network traffic usage in hourly, daily, monthly and full summary report.
For installing VnStat refer here
16. Nagios – Network/Server Monitoring
Nagios is an leading open source powerful monitoring system that enables network/system administrators to identify and resolve server related problems before they affect major business processes. With the Nagios system, administrators can able to monitor remote Linux, Windows, Switches, Routers and Printers on a single window. It shows critical warnings and indicates if something went wrong in your network/server which indirectly helps you to begin remediation processes before they occur.
For installing Nagios refer here