I have a system with a dedicated swap partition, running a custom distribution generated by Yocto.
On startup, during init, I can see the first swapon command successfully activating the swap space. A second swapon is sent, which subsequently fail (with a
swapon failed: Device or resource busy since the swap partition has already been activated).
However, once fully started, I realised the swap space was not used by the system and is shown as deleted by
swapon --show and
root@machine:~# swapon --show Filename Type Size Used Priority /dev/mmcblk0p4 (deleted) partition 1023996 0 -1
I wonder what causes the swap partition to be shown as deleted?