loading Posted November 14, 2012 Share Posted November 14, 2012 Need to monitor Linux server performance? Try these built-in commands and a few add-on tools. Most Linux distributions are equipped with tons of monitoring. These tools provide metrics which can be used to get information about system activities. You can use these tools to find the possible causes of a performance problem. The commands discussed below are some of the most basic commands when it comes to system analysis and debugging server issues such as: 1. Finding out bottlenecks. 2. Disk (storage) bottlenecks. 3. CPU and memory bottlenecks. 4. Network bottlenecks #1: top - Process Activity Command The top program provides a dynamic real-time view of a running system i.e. actual process activity. By default, it displays the most CPU-intensive tasks running on the server and updates the list every five seconds. This is the hidden content, please Sign In or Sign Up Commonly Used Hot Keys The top command provides several useful hot keys This is the hidden content, please Sign In or Sign Up => Related: How do I Find Out Linux CPU Utilization? This is the hidden content, please Sign In or Sign Up This is the hidden content, please Sign In or Sign Up The command vmstat reports information about processes, memory, paging, block IO, traps, and cpu activity. This is the hidden content, please Sign In or Sign Up Sample Outputs This is the hidden content, please Sign In or Sign Up Display Memory Utilization Slabinfo This is the hidden content, please Sign In or Sign Up Get Information About Active / Inactive Memory Pages This is the hidden content, please Sign In or Sign Up => Related: This is the hidden content, please Sign In or Sign Up This is the hidden content, please Sign In or Sign Up w command displays information about the users currently on the machine, and their processes This is the hidden content, please Sign In or Sign Up Sample Outputs: This is the hidden content, please Sign In or Sign Up #4: uptime - Tell How Long The System Has Been Running The uptime command can be used to see how long the server has been running. The current time, how long the system has been running, how many users are currently logged on, and the system load averages for the past 1, 5, and 15 minutes This is the hidden content, please Sign In or Sign Up Output: 18:02:41 up 1 day, 23:42, 1 user, load average: 0.00, 0.00, 0.00 1 can be considered as optimal load value. The load can change from system to system. For a single CPU system 1 - 3 and SMP systems 6-10 load value might be acceptable. 1 can be considered as optimal load value. The load can change from system to system. For a single CPU system 1 - 3 and SMP systems 6-10 load value might be acceptable. This is the hidden content, please Sign In or Sign Up ps command will report a snapshot of the current processes. To select all processes use the -A or -e option: This is the hidden content, please Sign In or Sign Up Sample Outputs: This is the hidden content, please Sign In or Sign Up ps is just like top but provides more information. Show Long Format Output This is the hidden content, please Sign In or Sign Up To turn on extra full mode (it will show command line arguments passed to process): This is the hidden content, please Sign In or Sign Up To See Threads ( LWP and NLWP) This is the hidden content, please Sign In or Sign Up To See Threads After Processes This is the hidden content, please Sign In or Sign Up Print All Process On The Server This is the hidden content, please Sign In or Sign Up This is the hidden content, please Sign In or Sign Up Print A Process Tree This is the hidden content, please Sign In or Sign Up This is the hidden content, please Sign In or Sign Up This is the hidden content, please Sign In or Sign Up Print Security Information This is the hidden content, please Sign In or Sign Up euser,ruser,suser,fuser,f,comm,label This is the hidden content, please Sign In or Sign Up This is the hidden content, please Sign In or Sign Up See Every Process Running As User Vivek This is the hidden content, please Sign In or Sign Up Set Output In a User-Defined Format This is the hidden content, please Sign In or Sign Up Display Only The Process IDs of Lighttpd This is the hidden content, please Sign In or Sign Up This is the hidden content, please Sign In or Sign Up This is the hidden content, please Sign In or Sign Up Display The Name of PID 55977 This is the hidden content, please Sign In or Sign Up Find Out The Top 10 Memory Consuming Process This is the hidden content, please Sign In or Sign Up Find Out top 10 CPU Consuming Process This is the hidden content, please Sign In or Sign Up #6: free - Memory Usage The command free displays the total amount of free and used physical and swap memory in the system, as well as the buffers used by the kernel. # free Sample Output: This is the hidden content, please Sign In or Sign Up => Related: : 1. This is the hidden content, please Sign In or Sign Up 2. This is the hidden content, please Sign In or Sign Up 3. This is the hidden content, please Sign In or Sign Up #7: This is the hidden content, please Sign In or Sign Up The command iostat report Central Processing Unit (CPU) statistics and input/output statistics for devices, partitions and network filesystems (NFS). This is the hidden content, please Sign In or Sign Up Sample Outputs: This is the hidden content, please Sign In or Sign Up => Related: This is the hidden content, please Sign In or Sign Up #8: sar - Collect and Report System Activity The sar command is used to collect, report, and save system activity information. To see network counter, enter: This is the hidden content, please Sign In or Sign Up To display the network counters from the 24th: This is the hidden content, please Sign In or Sign Up You can also display real time usage using sar: This is the hidden content, please Sign In or Sign Up Sample Outputs: This is the hidden content, please Sign In or Sign Up => Related: This is the hidden content, please Sign In or Sign Up #9: mpstat - Multiprocessor Usage The mpstat command displays activities for each available processor, processor 0 being the first one. mpstat -P ALL to display average CPU utilization per processor: This is the hidden content, please Sign In or Sign Up Sample Output: This is the hidden content, please Sign In or Sign Up => Related: This is the hidden content, please Sign In or Sign Up #10: pmap - Process Memory Usage The command pmap report memory map of a process. Use this command to find out causes of memory bottlenecks. This is the hidden content, please Sign In or Sign Up Sample Outputs: This is the hidden content, please Sign In or Sign Up The last line is very important: mapped: 933712K total amount of memory mapped to files writeable/private: 4304K the amount of private address space shared: 768000K the amount of address space this process is sharing with others => Related: This is the hidden content, please Sign In or Sign Up #11 and #12: netstat and ss - Network Statistics The command netstat displays network connections, routing tables, interface statistics, masquerade connections, and multicast memberships. ss command is used to dump socket statistics. It allows showing information similar to netstat. See the following resources about ss and netstat commands: This is the hidden content, please Sign In or Sign Up This is the hidden content, please Sign In or Sign Up #13: iptraf - Real-time Network Statistics The iptraf command is interactive colorful IP LAN monitor. It is an ncurses-based IP LAN monitor that generates various network statistics including TCP info, UDP counts, ICMP and OSPF information, Ethernet load info, node stats, IP checksum errors, and others. It can provide the following info in easy to read format: Network traffic statistics by TCP connection IP traffic statistics by network interface Network traffic statistics by protocol Network traffic statistics by TCP/UDP port and by packet size Network traffic statistics by Layer2 address This is the hidden content, please Sign In or Sign Up This is the hidden content, please Sign In or Sign Up #14: tcpdump - Detailed Network Traffic Analysis The tcpdump is simple command that dump traffic on a network. However, you need good understanding of TCP/IP protocol to utilize this tool. For.e.g to display traffic info about DNS, enter: This is the hidden content, please Sign In or Sign Up To display all IPv4 HTTP packets to and from port 80, i.e. print only packets that contain data, not, for example, SYN and FIN packets and ACK-only packets, enter: This is the hidden content, please Sign In or Sign Up To display all FTP session to 202.54.1.5, enter: This is the hidden content, please Sign In or Sign Up To display all HTTP session to 192.168.1.5: This is the hidden content, please Sign In or Sign Up use This is the hidden content, please Sign In or Sign Up information about files, enter: This is the hidden content, please Sign In or Sign Up #15: strace - System Calls Trace system calls and signals. This is useful for debugging webserver and other server problems. See how to use to This is the hidden content, please Sign In or Sign Up see What it is doing. #16: /Proc file system - Various Kernel Statistics /proc file system provides detailed information about various hardware devices and other Linux kernel information. See This is the hidden content, please Sign In or Sign Up documentations for further details. Common /proc examples: This is the hidden content, please Sign In or Sign Up 17#: Nagios - Server And Network Monitoring This is the hidden content, please Sign In or Sign Up is a popular open source computer system and network monitoring application software. You can easily monitor all your hosts, network equipment and services. It can send alert when things go wrong and again when they get better. This is the hidden content, please Sign In or Sign Up "Fully Automated Nagios". FAN goals are to provide a Nagios installation including most tools provided by the Nagios Community. FAN provides a CDRom image in the standard ISO format, making it easy to easilly install a Nagios server. Added to this, a wide bunch of tools are including to the distribution, in order to improve the user experience around Nagios. 18#: Cacti - Web-based Monitoring Tool Cacti is a complete network graphing solution designed to harness the power of RRDTool's data storage and graphing functionality. Cacti provides a fast poller, advanced graph templating, multiple data acquisition methods, and user management features out of the box. All of this is wrapped in an intuitive, easy to use interface that makes sense for LAN-sized installations up to complex networks with hundreds of devices. It can provide data about network, CPU, memory, logged in users, Apache, DNS servers and much more. See how This is the hidden content, please Sign In or Sign Up tool under CentOS / RHEL. #19: KDE System Guard - Real-time Systems Reporting and Graphing KSysguard is a network enabled task and system monitor application for KDE desktop. This tool can be run over ssh session. It provides lots of features such as a client/server architecture that enables monitoring of local and remote hosts. The graphical front end uses so-called sensors to retrieve the information it displays. A sensor can return simple values or more complex information like tables. For each type of information, one or more displays are provided. Displays are organized in worksheets that can be saved and loaded independently from each other. So, KSysguard is not only a simple task manager but also a very powerful tool to control large server farms. This is the hidden content, please Sign In or Sign Up See This is the hidden content, please Sign In or Sign Up for detailed usage. #20: Gnome System Monitor - Real-time Systems Reporting and Graphing The System Monitor application enables you to display basic system information and monitor system processes, usage of system resources, and file systems. You can also use System Monitor to modify the behavior of your system. Although not as powerful as the KDE System Guard, it provides the basic information which may be useful for new users: Displays various basic information about the computer's hardware and software. Linux Kernel version GNOME version Hardware Installed memory Processors and speeds System Status Currently available disk space Processes Memory and swap space Network usage File Systems Lists all mounted filesystems along with basic information about each. This is the hidden content, please Sign In or Sign Up Bonus: Additional Tools A few more tools: This is the hidden content, please Sign In or Sign Up - scan your server for open ports. This is the hidden content, please Sign In or Sign Up - list open files, network connections and much more. This is the hidden content, please Sign In or Sign Up web based tool - ntop is the best tool to see network usage in a way similar to what top command does for processes i.e. it is network traffic monitoring software. You can see network status, protocol wise distribution of traffic for UDP, TCP, DNS, HTTP and other protocols. This is the hidden content, please Sign In or Sign Up - Another good monitoring tool for the X Window System. It is highly configurable and is able to monitor many system variables including the status of the CPU, memory, swap space, disk storage, temperatures, processes, network interfaces, battery power, system messages, e-mail inboxes etc. Link to comment Share on other sites More sharing options...
J4XPL01T3R Posted November 14, 2012 Share Posted November 14, 2012 Re: 20 Linux System Monitoring Tools Every SysAdmin Should Know Copy/Pasted from TF mega_shock: Link to comment Share on other sites More sharing options...
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