6 Ways to Check Memory Usage in Linux: A Comprehensive Guide

If you’re a Linux user, you may be curious about how to check the memory usage of your system. Understanding memory usage is essential for optimizing system performance, identifying memory leaks, and troubleshooting issues. In this article, we’ll explore how to check memory usage in Linux and provide step-by-step instructions.

Introduction to Memory Usage in Linux

Before we dive into checking memory usage, it’s essential to understand what memory usage means in Linux. Memory usage refers to the amount of memory that’s being used by processes on the system. This can include the operating system, applications, and other services. Memory usage is measured in kilobytes, megabytes, and gigabytes.

Checking Memory Usage with the Free Command

The free command is the simplest and easiest way to check memory usage in Linux. The free command displays information about the total amount of memory, the amount of memory that’s currently in use, and the amount of memory that’s available. Here’s how to use the free command:

1. Open a terminal window.
2. Type the following command and press Enter: free -m
3. The output will display the total amount of memory, the amount of memory that’s currently in use, the amount of memory that’s free, and the amount of memory that’s being used as buffers and cache.

Checking Memory Usage with the Top Command

The top command is another useful command for checking memory usage in Linux. The top command provides a real-time view of system processes and their memory usage. Here’s how to use the top command:

1. Open a terminal window.
2. Type the following command and press Enter: top
3. The output will display a list of system processes, along with their CPU usage, memory usage, and other information. To sort the list by memory usage, press the M key.

Checking Memory Usage with the Ps Command

The ps command is a useful command for checking the memory usage of specific processes on the system. Here’s how to use the ps command:

1. Open a terminal window.
2. Type the following command and press Enter: ps aux | awk '{print $6/1024 " MB\t\t" $11}' | sort -n
3. The output will display a list of processes sorted by memory usage, along with the amount of memory used by each process.

Checking Memory Usage with the Htop Command

The htop command is another useful command for checking memory usage in Linux. The htop command provides a real-time view of system processes and their memory usage, similar to the top command. Here’s how to use the htop command:

1. Open a terminal window.
2. Type the following command and press Enter: htop
3. The output will display a list of system processes, along with their CPU usage, memory usage, and other information. To sort the list by memory usage, press the F6 key and select MEM%.

Checking Memory Usage with the Vmstat Command

The vmstat command provides detailed information about system memory usage, including the amount of memory used by processes, the amount of memory used for buffers and cache, and more. Here’s how to use the vmstat command:

1. Open a terminal window.
2. Type the following command and press Enter: vmstat -s
3. The output will display detailed information about system memory usage, including the total amount of memory, the amount of memory that’s currently in use, and the amount of memory that’s free.

Checking Memory Usage with the Proc File System

The proc file system is a virtual file system in Linux that provides information about system processes and their memory usage. Here’s how to use the proc file system to check memory usage:

1. Open a terminal window.
2. Type the following command and press Enter: cat /proc/meminfo
3. The output will display detailed information about system memory usage, including the total amount of memory, the amount of memory that’s currently in use, and the amount of memory that’s free.

Checking Memory Usage with the Glances Command

The Glances command is a powerful system monitoring tool that provides real-time information about system processes and their resource usage, including memory usage. Here’s how to use the Glances command:

1. Install the Glances package by typing the following command and pressing Enter: sudo apt-get install glances
2. Once the package is installed, type the following command and press Enter: glances
3. The Glances command will launch, displaying a real-time view of system processes and their resource usage, including memory usage.

Conclusion

In conclusion, understanding how to check memory usage in Linux is essential for optimizing system performance, identifying memory leaks, and troubleshooting issues. In this article, we’ve explored six different methods for checking memory usage in Linux, including the free command, the top command, the ps command, the htop command, the vmstat command, and the proc file system.

We’ve also introduced the powerful Glances command, which provides real-time system monitoring and resource usage information. By using these tools, Linux users can gain a better understanding of their system’s memory usage and ensure optimal performance.

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