swapon: /swapfile: read swap header failed: Invalid argument

Question

#sudo dd if=/dev/zero of=/swapspacefile bs=1M count=2048k

  0+0 records in
  0+0 records out
  0 bytes (0 B) copied, 0.000417928 s, 0.0 kB/s

#chmod 600 /swapspacefile

   mkswap: error: swap area needs to be at least 40 KiB

   Usage:
     mkswap [options] device [size]

   Options:
     -c, --check               check bad blocks before creating the swap area
     -f, --force               allow swap size area be larger than device
     -p, --pagesize SIZE       specify page size in bytes
     -L, --label LABEL         specify label
     -v, --swapversion NUM     specify swap-space version number
     -U, --uuid UUID           specify the uuid to use
     -V, --version             output version information and exit
     -h, --help                display this help and exit


#sudo mkswap /swapspacefile

but it throws below when I excute the,

  swapon: /swapfile: insecure permissions 0644, 0600 suggested.
  swapon: /swapfile: read swap header failed: Invalid argument

Answer 1

I read this from the comments, but I thought I would be visible as an answer.

# mkswap /swapfile

You should run this command to prepare the file to be used as a swap space.