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What are the columns in top?

What are the columns in top?

The default columns, with descriptions, include:

  • PID – Process ID.
  • USER – Name of the effective user (owner) of the process.
  • PR – Priority.
  • NI – Nice value.
  • VIRT – virtual memory size.
  • RES – resident memory size.
  • SHR – shared memory size.

What is the use of top command in Unix?

The Unix top command is a very useful way to see what programs are currently running on the system and how heavily they are using system resources. (The command is named “top” because it shows the top users of the system.)

What does top mean in Unix?

table of processes
top (table of processes) is a task manager program, found in many Unix-like operating systems, that displays information about CPU and memory utilization.

How do you understand top command?

S – indicates the status of the process: S=sleep R=running Z=zombie (S) %CPU – This is the percentage of CPU used by this process (0.3) %MEM – This is the percentage of RAM used by the process (0.7) TIME+ –This is the total time of activity of this process (0:17.75)

What is virtual memory in top command?

VIRT stands for the virtual size of a process, which is the sum of memory it is actually using, memory it has mapped into itself (for instance the video card’s RAM for the X server), files on disk that have been mapped into it (most notably shared libraries), and memory shared with other processes.

What is the difference between virtual and resident memory?

resident memory typically refers to physical RAM installed in the machine. virtual memory is Hard Disk space reserved for the O/S to act as RAM. The O/S “swaps” data in and out of the virtual memory to place it in RAM, or to take it out of RAM.

What is the function of top command?

Display and update information about the top CPU processes
top/Function

What is virtual memory and its example?

An imaginary memory area supported by some operating systems (for example, Windows but not DOS) in conjunction with the hardware. For example, virtual memory might contain twice as many addresses as main memory. A program using all of virtual memory, therefore, would not be able to fit in main memory all at once.

How do I check my virtual memory?

In the Performance area, click the Settings button. The Performance Options dialog box appears. Click the Advanced tab in the Performance Options dialog box. Information about virtual memory appears near the bottom of the dialog box.

What is virtual set size?

VSZ – Virtual Set Size The Virtual Set Size is a memory size assigned to a process ( program ) during the initial execution. The Virtual Set Size memory is simply a number of how much memory a process has available for its execution.

What is the purpose of the top command in Unix?

top is a basic Unix command which is very useful for observing the current state of your Unix system, by default presenting you the list of top users of your system’s resources – CPU shares and memory. Basic usage of the top command

Where is the top of the command column?

The COMMAND column is off-screen, to the right—it didn’t fit in the image above, but we’ll see it shortly. Press Q to exit top. You can press the Up or Down Arrows, Home, End, and Page Up or Down keys to move up and down and access all the processes. Press the Left or Right Arrow to move the process list sideways.

What do you need to know about top in Linux?

Then you need “top,” which is a real-time process monitor command that helps monitor the running processes in a Linux system straight from the command line. “Top” displays system summary information and a list of all processes and threads currently being managed by the Linux kernel.

What is the default top output in Unix?

These are the elements which default top output consists of: Unix system uptime and average load This is the line of top which confirms how many hours (or even days!) your system has been up, shows you the number of logged in users, and reports the average system load numbers for the last minute, 5 minutes and 15 minutes.