Bytes on Pristine Swap Partition

swap.log

➜ tmp>truncate --size 1G testswap
➜ tmp>hexdump -C testswap
00000000  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
40000000


# Note the file starts as complete zeros
# Let's find out what happens when we "create/initialize" swap space

➜ tmp>mkswap -f testswap
Setting up swapspace version 1, size = 1048572 KiB
no label, UUID=5c1fddda-d28a-446e-8dc3-0e01c54389f7


# Sounds like something happened...
# And indeed the file is no longer all zeros:

➜ tmp>hexdump -C testswap
00000000  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00000400  01 00 00 00 ff ff 03 00  00 00 00 00 5c 1f dd da  |............\...|
00000410  d2 8a 44 6e 8d c3 0e 01  c5 43 89 f7 00 00 00 00  |..Dn.....C......|
00000420  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00000ff0  00 00 00 00 00 00 53 57  41 50 53 50 41 43 45 32  |......SWAPSPACE2|
00001000  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
40000000