You try a lot of Distributions next to Pisi Linux on your Hard Drive?
Also you make Distro hopping, on your HDD and not in the Virtualbox or an other Virtual Maschine.
And after you go back to Pisi Linux and you have lost you Swap partition.
No Problem here a little solution for it.
When you see in your System Monitor Swap 0,00GB/ and after no entrys have you lost your UUID (universally unique identifier) in the fstab.
The universally unique identifier
is an identifier standard used in software construction. A UUID is simply a 128-bit value. The meaning of each bit is defined by any of several variants.
For human-readable display, many systems use a canonical format using hexadecimal text with inserted hyphen characters. For example:
Read more about the UUID here: Universally unique identifier
When this number is wrong you have lost your Swap Partition but no Panic you can restore it.
open a Terminal and give in the following command:
The blkid command print for you, many important information such as device file, identification number, name and file system on the volumes contained in the attached storage media show.
Now let your Terminal open, and after that command open >Dolphin>Root and there go to /etc/fstab,
open the fstab with Admin rights Important only with Admin rights can you write in the fstab.
Check the numbers for the swap partition, when they are not correct change it. the UUID from the blkid command are always the correct UUID.
Delete the UUID in the fstab carefully so as you see above on the Image, from the first Number 4 to the last letter c.
Do not delete the complete Line
Now copy the UUID for the fstab from the Terminal and paste it in the fstab where you have remove the incorrect UUID when you are ready save it.
Close all Windows and make a reboot, after the reboot can you see your Swap Partition so as it was before.