Is it safe to only symlink /var/lib/docker/overlay2 to a different mounted volume?

Question says it all. I’d like the /var/lib/docker directory in my VM backup/snapshot, but not the overlay2 cache which can be easily recreated from the container setups.

Moving everything elsewhere would mean no longer having a backup for my persistent data in the volumes. Keeping overlay2 in place kills my machine when there is heavy development going on (disk full)

So, I was wondering if I could simply move the overlay2 subdirectory only and symlink to it.

Can I?

Alternatively, I can create a volume and mount it at overlay2, which is less flexible but will almost certainly work.

The question more or less becomes, does the docker engine create hard links across subdirectories of /var/lib/docker. I tried the mounting scenario for volumes and overlays (two different mounts in /etc/fstab) but I did get an error when I started my containers.