Disable swap on Ubuntu

disable swap only for a current session

sudo swapoff -a

OrĀ 

sudo -s
crontab -e

And add

@reboot sudo swapoff -a  

Or ( best solution )

Open fstab file, type sudo nano /etc/fstab in terminal.

File’s contents would look like this:

proc            /proc           proc    nodev,noexec,nosuid 0       0
/host/ubuntu/disks/root.disk /               ext4    loop,errors=remount-ro 0       1
/host/ubuntu/disks/swap.disk none            swap    loop,sw         0       0
#/dev/sda10 /media/ASD  vfat    defaults    0   0
#/dev/sda1  /media/98   vfat    defaults    0   0

Just add hash (#) to the beginning of the swap partition line, so the line looks as:

#/host/ubuntu/disks/swap.disk none            swap    loop,sw         0       0

Reboot your PC

References
https://askubuntu.com/questions/214805/how-do-i-disable-swap

Enable linux swap partition

You have no configuration for swap in /etc/fstab . Add following line to that file:

UUID=<uuid> none   swap    sw    0       0   

You have to replace with the uuid of your swap partition. To do that, run sudo blkid

$ sudo blkid
/dev/sda1: LABEL="System Reserved" UUID="88A0D0A1A0D09752" TYPE="ntfs" 
/dev/sda2: UUID="0620D9F920D9EFA3" TYPE="ntfs" 
/dev/sda5: UUID="c282b418-2045-4852-8789-88a44360a0bb" TYPE="ext4" 
/dev/sda6: UUID="f99c6a0c-790a-45ca-a1a9-8874f5a2999b" TYPE="ext4" 
/dev/sda7: UUID="4cc2e909-ebd1-4c72-abee-aa32035bf330" TYPE="swap"

References
http://askubuntu.com/questions/194775/swap-not-available-i-must-manually-swapon-after-every-reboot