Docker's documentation is clear: if possible and your kernel supports it, use overlay2 as the storage driver, as stated here: https://docs.docker.com/storage/storagedriver/overlayfs-driver/
Note : If you use OverlayFS, use the
overlay2driver rather than the
overlaydriver, because it is more efficient in terms of inode utilization. To use the new driver, you need version 4.0 or higher of the Linux kernel, or RHEL or CentOS using version 3.10.0-514 and above.
However, ECE's documentation and installation script says otherwise and recommends
overlay2 during the prereq check phase:
Checking Docker storage driver...
- The installation with overlay2 can proceed; however, we recommend using overlay
... and, confusingly, the official Ansible playbook sets overlay2 as the storage driver when installing ECE on RHEL7.
Why the discrepancy, and why recommend
overlay2 when Docker themselves recommends otherwise?