Description
Hello, I can't find from the docs, what is the difference between parent and top level IDs in context of the subvolume list command? To me them seems be the same.
sudo btrfs subvolume list -p /
ID 256 gen 00000 parent 5 top level 5 path root
ID 257 gen 00000 parent 5 top level 5 path home
ID 256 gen 00000 parent 257 top level 257 path /var/lib/machines
...
I found only the following and it doesn't help at all:
For every subvolume the following information is shown by default:
ID ID gen generation top level parent_ID path path
where ID is subvolume's (root)id, generation is an internal counter which is updated every transaction, parent_ID is the same as the parent subvolume's id, and path is the relative path of the subvolume to the top level subvolume. The subvolume's ID may be used by the subvolume set-default command, or at mount time via the subvolid= option.
...
Field selection:
-p print the parent ID (parent here means the subvolume which contains this subvolume).
https://github.com/kdave/btrfs-progs/blob/devel/Documentation/btrfs-subvolume.rst