How does Linux Top work?

top command is used to show the Linux processes. It provides a dynamic real-time view of the running system. Usually, this command shows the summary information of the system and the list of processes or threads which are currently managed by the Linux Kernel.

Where does top get its data from?

Top gets most of its information from several files under the /proc directory. You might already be aware that this directory provides users with a broad range of system-wide statistics, but thanks to top, we can summarize most of them inside a single organized window.

What does top output mean Linux?

“Top” displays system summary information and a list of all processes and threads currently being managed by the Linux kernel. It is also an interactive program, meaning that the output can be customized and manipulated while it’s running.

How do I run a top command in Linux?

The top Command Interface

You can open the Terminal either through the system Dash or the Ctrl+Alt+T shortcut. The upper part of the output shows statistics about the processes and resource usage. The lower part displays a list of currently running processes.

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What is VSZ in top?

2. VSZ Memory. VSZ is short for Virtual Memory Size. It’s the total amount of memory a process may hypothetically access. It accounts for the size of the binary itself, any linked libraries, and any stack or heap allocations.

How do you read top memory usage?

Viewing memory usage in top

Hit Shift+M to see the list sorted by memory usage. Your display may look slightly different than this example from a running Fedora Workstation: There are three columns showing memory usage to examine: VIRT, RES, and SHR.

How do I get more RAM on Linux?

Linux

  1. Open the command line.
  2. Type the following command: grep MemTotal /proc/meminfo.
  3. You should see something similar to the following as output: MemTotal: 4194304 kB.
  4. This is your total available memory.

Why we use top command in Linux?

The top command (table of processes) displays the processor activity of your Linux box and also displays tasks managed by the kernel in real-time. It also shows information about CPU and memory utilization of a list of running processes.

How do you run a top?

Key Switches for the ‘top’ Command

  1. -h: Show the current version.
  2. -c: This toggles the command column between showing command and program name.
  3. -d: Specify the delay time between refreshing the screen.
  4. -o: Sorts by the named field.
  5. -p: Only show processes with specified process IDs.

What is the difference between top and ps command in Linux?

top enables you to see your processes ordered by the amount of processor power they use. ps enables you to see all your processes, or just the processes used by certain users, for example root or yourself.

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Is Htop better than top?

Why Htop is Better Than Top Monitoring Tool

It has a nicer text-graphics interface, with colored output. It is easy to use and highly configurable. Allows for scrolling process list vertically and horizontally to see all processes and complete command lines. It also displays a process tree and comes with mouse support.

How do I find the top 10 processes in Linux?

The ps command command displays every process ( -e ) with a user-defined format ( -o pcpu ). First field is pcpu (cpu utilization). It is sorted in reverse order to display top 10 CPU eating process.

What does the top command do?

The top command is used to show the active Linux processes. It provides a dynamic real-time view of the running system. Usually, this command shows the summary information of the system and the list of processes or threads which are currently managed by the Linux kernel.

What is RES in top command?

RES stands for the resident size, which is an accurate representation of how much actual physical memory a process is consuming. (This also corresponds directly to the %MEM column.) This will virtually always be less than the VIRT size, since most programs depend on the C library.

How do you see the full command in top?

See the Full Command Line

Pressing “c” toggles the COMMAND column between displaying the process name and the full command line. To see a “tree” of processes that were launched or spawned by other processes, press V.