How to Gather RAM data?

What is RAM?

RAM is a form of computer memory that can be read and changed in any order, typically used to store working data and machine code.It is volatile in nature and store all inputs and data from the system boot up.

Why Gather RAM data?

Volatile memory contains the following system artifacts which gets lost when the device is restarted or shut down. The following artifacts can be expected out of the volatile memory acquisition process:

System Process
Running services
Clipboard Information
Browsing Sessions (Incognito Sessions)
Passwords
Accessed Files and Multimedia
Chats/Running Application stored data
user IDs and passwords
unsaved files

The steps for acquisition are as follows:

Determine the state of the machine
Identify the operating system
Check for authentic device access
Insert acquisition media
Perform Volatile Memory Dump
Collect SWAP, PAGEFILE.sys and system protected files
Hash and verify the acquired files
Create copies

Read RAM on top of linux system as follows by the help of LiME(Linux Memory Extractor):

Lime is a Loadable Kernel Module (LKM) which allows for volatile memory acquisition from Linux and Linux-based devices, such as Android. This makes LiME unique as it is the first tool that allows for full memory captures on Android devices. It also minimises its interaction between user and kernel space processes during acquisition, which allows it to produce memory captures that are more forensically sound than those of other tools designed for Linux memory acquisition.