In the normal sense of a "file"system, swap is not formatted as a file system.
It is formatted similar to memory or RAM.
No
No
A swap partiton because it is a dedicated partition and not a file
The only one I can think of is the swap partition, seeing as how it's not even a filesystem, just a place to dump pages. However, I'm sure there's even a filesystem driver somewhere for it.
82
A swap partition is used when the amount of RAM in a computer is already full. But this is not a recommended alternative to RAM space because it has slower access time.
Linux swap partition has the code 82 (hex). A swap partition must be formatted with mkswap before first use. You can use swapon and swapoff utilities to enable/disable swap
mkfs -t ext4 /dev/
It uses the swap. The swap is a dedicated partition and not a file.
The command is mkfs. Though usually most people will use: mkfs.<filesystem type> /dev/sdXY Where X is the drive and Y is the partition. For example: mkfs.ext4 /dev/sda3 means "Create an ext4 filesystem on the third partition of the first drive."
You need root privileges, and it's often best not to use fsck on a live (mounted.) filesystem. Also you'll need to know the device file and, in some cases, the filesystem of the partition you're working on. The command is thusly: # fsck /dev/sdXY In most cases the fsck command will figure out what the filesystem is and run the appropriate filesystem checker.
You do not need to set up a dedicated partition for swap as you can also set up a swap file.
Swap partition