Test with overlaybd

**Describe the solution you'd like:**
Currently the recommendation is to use devmapper for the volume images. But we should test with overlaybd as well:

https://github.com/containerd/overlaybd

**Why do you want this feature:**

There has been some anecdotal reports of performance issues with devmapper, especially when used over a prolonged period of time.

**Anything else you would like to add:**
[Miscellaneous information that will assist in solving the issue.]

Start by reviewing the linked overlaybd project and how Flintlock currently recommends devmapper for volume images. Compare overlaybd with devmapper for the reported prolonged-use performance concerns, and document the test results and any resulting recommendation.

Written by the indexing model from the issue text.