Memory

The systemctl command has multiple options to show the memory usage. With the status subcommand followed by the service, it will show the basics, including memory usage. To retrieve the information that easier to parse, then use show followed by --property=MemoryCurrent and the service name. Usage The status output will include memory usage. systemctl status nginx ● nginx.service - A high performance web server and a reverse proxy server Loaded: loaded (/lib/systemd/system/nginx.

Physical RAM is used to store information. Linux divides this RAM into smaller chunks, named memory pages. When there is no more normal memory available, the Linux kernel might need to temporarily store information aside. This is called paging or swap space. During the process of paging, memory pages will be moved from the RAM to the disk. This way memory is freed up for active processes, while older information is temporarily stored on the disk.

All hardware exposed

Every operating system needs memory to store program code segments and data. This is also true for Linux systems. The problem: there is a lot of information available regarding memory usage and its behavior. Let’s discover how Linux manages its memory and how we can gather memory information. After reading this guide, you will be able to: Show the total amount of memory Display all memory details Understand the details listed in /proc/meminfo Use tools like dmesg, dmidecode, free, and vmstat Linux memory information Random access memory When we talk about memory in this article, we usually mean random access memory (RAM).

Configuring ASLR with randomize_va_space The Linux kernel has a defense mechanism named address space layout randomization (ASLR). This setting is tunable with the randomize_va_space setting. Before making changes to this setting, it is good to understand what this Linux security measure actually does and how it works. Understanding ASLR In 2001 the term ASLR was first introduced as a patch to the Linux kernel. Its main goal was to randomize memory segments to make abuse by malicious programs harder.

Everyone who used Windows 95 or 98 in the past is familiar with the concept of failure. One crashing application was enough to bring the system to a halt. Fortunately, Linux systems have a strong foundation, including privilege separation and memory management. When things go wrong, the impact is reduced to a minimum. This is called containment. Linux Memory Management Memory is like your the storage capacity of your brain. Every bit should be stored properly, or otherwise you will do strange things.