8 Command Line Tools to Monitor Linux Performance

http://www.tecmint.com/command-line-tools-to-monitor-linux-performance/

It’s really very tough job for every System or Network administrator to monitor and debugLinux System Performance problems every day. After being a Linux Administrator for 5 years in IT industry, I came to know that how hard is to monitor and keep systems up and running. For this reason, we’ve compiled the list ofTop 8 frequently used command line monitoring tools that might be useful for everyLinux/Unix System Administrator. These commands are available under all flavors ofLinux and can be useful to monitor and find the actual causes of performance problem. This list of commands shown here are very enough for you to pick the one that is suitable for your monitoring scenario.

 

8 Linux Command Line Performance Monitoring Tools

 

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 manyLinux/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 displayCPU usage, Memory usage, Swap Memory,Cache Size, Buffer Size, Process PID,User, Commands and much more. It also shows highmemory 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.

# top

 

Top Command Example

 

For more examples of Top command read : 12 TOP Command Examples in Linux

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 calledsysstat that includes a vmstat program. The common usage of command format is.

# vmstatprocs -----------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

For more Vmstat examples read : 6 Vmstat Command Examples in Linux

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 aredisk 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.

# lsofCOMMAND     PID      USER   FD      TYPE     DEVICE     SIZE       NODE NAMEinit          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/initinit          1      root  mem       REG      104,2   129900     196453 /lib/ld-2.5.soinit          1      root  mem       REG      104,2  1693812     196454 /lib/libc-2.5.soinit          1      root  mem       REG      104,2    20668     196479 /lib/libdl-2.5.soinit          1      root  mem       REG      104,2   245376     196419 /lib/libsepol.so.1init          1      root  mem       REG      104,2    93508     196431 /lib/libselinux.so.1init          1      root   10u     FIFO       0,17                 953 /dev/initctl

More lsof command usage and examples : 10 lsof Command Examples in Linux

4. Tcpdump – Network Packet Analyzer

Tcpdump one of the most widely used command-line network packet analyzer orpackets 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 eth0tcpdump: verbose output suppressed, use -v or -vv for full protocol decodelistening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes22:08:59.617628 IP tecmint.com.ssh > 115.113.134.3.static-mumbai.vsnl.net.in.28472: P 2532133365:2532133481(116) ack 3561562349 win 964822:09:07.653466 IP tecmint.com.ssh > 115.113.134.3.static-mumbai.vsnl.net.in.28472: P 116:232(116) ack 1 win 964822:08:59.617916 IP 115.113.134.3.static-mumbai.vsnl.net.in.28472 > tecmint.com.ssh: . ack 116 win 64347

For more tcpdump usage read : 12 Tcpdump Command Examples in Linux

5. Netstat – Network Statistics

Netstat is a command line tool for monitoring incoming andoutgoing 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 | moreActive Internet connections (servers and established)Proto Recv-Q Send-Q Local Address               Foreign Address             Statetcp        0      0 *:mysql                     *:*                         LISTENtcp        0      0 *:sunrpc                    *:*                         LISTENtcp        0      0 *:realm-rusd                *:*                         LISTENtcp        0      0 *:ftp                       *:*                         LISTENtcp        0      0 localhost.localdomain:ipp   *:*                         LISTENtcp        0      0 localhost.localdomain:smtp  *:*                         LISTENtcp        0      0 localhost.localdomain:smtp  localhost.localdomain:42709 TIME_WAITtcp        0      0 localhost.localdomain:smtp  localhost.localdomain:42710 TIME_WAITtcp        0      0 *:http                      *:*                         LISTENtcp        0      0 *:ssh                       *:*                         LISTENtcp        0      0 *:https                     *:*                         LISTEN

More Netstat examples : 20 Netstat Command Examples in Linux.

6. Htop – Linux Process Monitoring

Htop is a much advanced interactive and real time Linux process monitoring tool. This is much similar to Linuxtop 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 usingYUM package manager tool. For more information on installation read our article below.

# htop

 

Htop Command Example Screenshot

 

For Htop installation read : Install Htop (Linux Process Monitoring) in Linux

7. Iotop – Monitor Linux Disk I/O

Iotop is also much similar to top command andHtop program, but it has accounting function to monitor and display real timeDisk I/O and processes. This tool is much useful for finding the exact process and high used disk read/writes of the processes.

# iotop

 

Iotop Command Example Screenshot

 

For Ioptop installation and usage read : Install Iotop in Linux

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 includingdevices, local disks, remote disks such asNFS.

# iostatLinux 2.6.18-238.9.1.el5 (tecmint.com)         09/13/2012avg-cpu:  %user   %nice %system %iowait  %steal   %idle           2.60    3.65    1.04    4.29    0.00   88.42Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtncciss/c0d0       17.79       545.80       256.52  855159769  401914750cciss/c0d0p1      0.00         0.00         0.00       5459       3518cciss/c0d0p2     16.45       533.97       245.18  836631746  384153384cciss/c0d0p3      0.63         5.58         3.97    8737650    6215544cciss/c0d0p4      0.00         0.00         0.00          8          0cciss/c0d0p5      0.63         3.79         5.03    5936778    7882528cciss/c0d0p6      0.08         2.46         2.34    3847771    3659776

For more Iostat usage and examples visit : 6 Iostat Command Examples in Linux

We would like to know what kind of monitoring programs you use tomonitor performance of your Linux servers? If we’ve missed any important tool that you would like us to include in this list, please inform us via comments and please don’t forget to share it.