How do I add Swap partition after the installation has been done?

Question

I recently dual booted my computer, Antergos (with Gnome) with existing Ubuntu Gnome 17.04 installation. and I noticed that Gnome shell in Antergos features a Hibernation button which was not present in Gnome shell with Ubuntu. But when I tried to click that button, my computer won't hibernate. I've a swap partition but currently Ubuntu installation is using it. I want that swap partition to be used by Antergos for hibernation purpose.

output of lsblk ran from Antergos

NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda      8:0    0 111.8G  0 disk 
├─sda1   8:1    0   7.6G  0 part 
├─sda2   8:2    0     1K  0 part 
├─sda5   8:5    0  19.1G  0 part 
├─sda6   8:6    0  47.7G  0 part 
├─sda7   8:7    0  18.6G  0 part /
└─sda8   8:8    0  18.8G  0 part /home

In the table above, sda1 is swap sda5 is /root for Ubuntu. sda6 is /home for Ubuntu and sda5 to sda8 are part of an extended partition.

keep in mind that my experience with anything that's based on Arch is too little (below 24 hours)

Answer 1

You can use the swap partition that your ubuntu install is also using.

First, determine the UUID of the partition:

root@darkstar:~ # blkid
/dev/sda1: UUID="1558f461-07af-47e5-a7ef-fe11a780f09f" TYPE="ext4" PARTUUID="0005e081-01"
/dev/sda2: UUID="5c00b21d-4569-4a00-b419-fd86be1be6f6" TYPE="swap" PARTUUID="0005e081-02"
/dev/sdb1: UUID="00eff59f-b759-4b3f-94ef-3e8c0371e714" TYPE="ext4" PARTUUID="cc26cc26-01"

So /dev/sda2 is my swap, and the UUID is 5c00b21d-4569-4a00-b419-fd86be1be6f6

Then add an entry in /etc/fstab:

UUID=5c00b21d-4569-4a00-b419-fd86be1be6f6 none swap sw 0 0

Then either reboot or run swapon /dev/sda1 or swapon -a