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

General Discussions
1

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.

2

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.