How to View Resident Memory Usage with htop/top in Your Machine

View Resident Memory Usage with htop/top in Global Topic

In this article, we will explore the concept of resident memory usage in the global topic of system administration and monitoring. We will cover key concepts, including physical memory, resident memory, and how to view resident memory consumption using the htop and top commands in Linux systems. Additionally, we will provide a reference list of books, articles, and online resources for further learning.

What is Resident Memory?

Resident memory, also known as resident set size (RSS), refers to the amount of physical memory that a process has loaded into its address space. Unlike virtual memory, which is a combination of physical memory and disk space, resident memory is solely physical memory that the operating system has allocated to a specific process. Resident memory is an essential metric for monitoring system performance and identifying memory leaks or other issues causing excessive memory usage.

Understanding Physical Memory

Physical memory, also known as RAM, is a hardware component that stores data and instructions for the CPU. Physical memory is volatile, meaning that it loses its contents when power is removed. Unlike virtual memory, physical memory is limited and cannot be extended indefinitely. Thus, monitoring and managing physical memory usage is crucial for maintaining system performance and stability.

Viewing Resident Memory Usage with htop

The htop command is a popular interactive process viewer for Linux systems. Htop provides a real-time, user-friendly interface for monitoring system performance, including memory usage. To view resident memory usage with htop, follow these steps:

1. Open a terminal window.
2. Type htop and press Enter.
3. Sort processes by memory usage by pressing the F6 key and selecting MEM%.
4. View the resident memory usage of each process in the RES column.

$ htop

[...]
  PID USER      PRI  NI  VIRT   RES   SHR S %CPU %MEM     TIME+  COMMAND
28424 user      20   0 43836 19312 12528 S  0.0  0.2   0:00.02 htop
[...]

Viewing Resident Memory Usage with top

The top command is another popular process viewer for Linux systems. While not as user-friendly as htop, top provides real-time monitoring of system performance, including memory usage. To view resident memory usage with top, follow these steps:

1. Open a terminal window.
2. Type top and press Enter.
3. Sort processes by memory usage by typing M and pressing Enter.
4. View the resident memory usage of each process in the RES column.

$ top

[...]
  PID USER      PR  NI    VIRT    RES    SHR S %CPU %MEM     TIME+ COMMAND
28424 user      20   0  43836k  19312k  12532 S  0.0  0.2   0:00.02 htop
[...]

Additional Tools for Monitoring Resident Memory Usage

While htop and top are popular tools for monitoring resident memory usage, other tools are available for more advanced monitoring and analysis, including:

• free: displays the total amount of physical and swap memory, along with usage statistics.
• pmap: displays the memory map of a process, including the size and location of memory segments.

References

• htop - an interactive process viewer for Unix systems
• top - display Linux processes
• free - display amount of free and used memory in the system
• pmap - report memory map of a process
• Memory Management in Linux
• Understanding memory management in Linux