Linux Memory (RAM) and Swap Management

Inspired by a collection of “Why is my machine swapping?” questions from our online communities, Nate and Scott will talk about Linux memory management. Starting from some basic commands like free and vmstat to view and report on memory usage, but also delving into the Linux kernel tunables that allow for customization of the memory management approach used by your system. Do you really need a swap? Well that actually depends, watch the show and find out!

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Critical Administration Skills for Red Hat Enterprise Linux: Whether you are new to Linux or new to RHEL, join our hosts for a hands-on look into the commands and processes, ask questions, and grow your knowledge.

Get Started with Red Hat Enterprise Linux: https://developers.redhat.com/register
Try it for yourself: https://redhat.com/interactive-labs
Join our Discord: https://red.ht/rhel-discord

Nate Lager:   / gangrif  
Scott McBrien:   / scott-mcbrien-349b356  

Tuned Interactive self-paced lab:
https://www.redhat.com/en/interactive...

Excellent article on how to set swappiness with maths to determine pagecache or anon page memory preference (by Chris Down from Meta):
https://chrisdown.name/2018/01/02/in-...

Commands used: free, vmstat, ps, top, swapon, pmap


Chapters
00:00 Stream start
00:43 Critical Path
16:00 Welcome
16:40 Virtual Memory vs. Memory
20:11 Do I need a swap?
22:06 How is swap used and how big should I make it?
27:19 What is swap used for?
28:13 Setting swappiness kernel tunable
36:38 Using the drop_caches kernel tunable
40:40 Process memory address spaces (pmap)
46:18 overcommit_memory kernel tunable
53:30 oom_killer scoring and priority and tunables
56:23 Wrap-up