Sharing Swap space between distributions

I just booted EndevourOS (ARCH based) and looked at the partition table using Gparted of my NUC.

MX Linux had labelled the two SWAP partitions as MX Linux.

I reformatted both Swap partitions. Then, I booted MX Linux to see it hangs up at booting (re-formatting SAWP partition). It did not but booted as usual.

Lot of these facts, I did not know. I have three distributions in my NUC and two Swap Partitions. My only concern is the speed of booting and smooth functioning when running. I won't install a distribution until I have tested it on a live USB, many a times. I write a piece in this blog site and review each new and past comments I have made. The other major concern is the compatibility of the Debian's GRUB file. 

I shun all distribution that run on root mode and Ubuntu is one of them I shun the most. 

DeepIn from China included.

It is mandatory one should run on a user level always unless one is doing some maintenance work.

I depend on chron jobs and deamons and do not run my NUC 24/7 like a server.

One who runs a Server should be very cautious, since even a Linux guy can become promised by another Linux guy with a hacker mentality. I never use Kali and Parrot OS, If I need any investigation. Tails has fallen out of my domain and Gparted does not have a Live CD iso probably due to concerns raised above. One has to install it as an application which I always do.

So I cannot format or erase SWAP partitions even if I wish to do so. Worse scenario I can mount an old Puppy Linux and format any partition at will. I used to do that with Knoppix and Knoppix cannot mount my integrated graphic card of my NUC in a live session.

I am not paranoid anyway.

Sharing Swap space between distributions

Sharing-is-caring asks: Is it possible to share swap space between multiple distros? Is it safe?

DistroWatch answers: Yes, it is possible to share the same swap partition across Linux distributions. Whichever distribution is running will keep track of where it writes data to the swap partition and ignore anything else in the swap space. Assuming each distribution is only running one at a time and you're not sharing a swap partition between two operating systems running in parallel, perhaps on virtual machines, there will be no problems with two distributions sharing the same swap space.

The question asked if sharing a swap partition is safe and I'm guessing the concern is with information leaking out from one operating system to another. This could happen, but it can happen whether the operating systems are sharing the same swap partition or if they're using separate swap partitions. Whichever operating system is running has full access to your hardware, meaning data written to one distro's swap partition can be read by another distro.

Let's say you have one trusted distribution (called Distro A) and one distribution with untrusted software running on it (Distro B). When Distro A is running it might write sensitive information, such as a password, to swap space. When Distro B runs a malicious program could scan the swap partition and find the password. This is true whether the two distributions share the same swap space or not. Any partition connected to the computer will be visible to both distributions and therefore still vulnerable to malicious programs running on Distro B.

If you're concerned about one distribution reading and compromising security by reading data left in your swap space, you can detach the swap partition and wipe it clean just before you shutdown your computer. Let's look at an example.

First, we need to determine on which partition our swap space is located. We can do this with the swapon command:

$ swapon -s

Filename	Type	Size	Used	Priority
/dev/sda2	partition	2047996	2816	-2

In this example we discover the swap partition is located at /dev/sda2. We will detach this swap partition with the swapoff command:

$ sudo swapoff /dev/sda2

Finally, we overwrite the swap partition (sda2 in this example) with random data. We can do this with the dd command:

$ sudo dd if=/dev/urandom of=/dev/sda2

At this point, if we restart the computer, whichever distribution we boot will not be able to see what was previously written to the swap partition.