Request: Option for pools to be either thick or thin provisioned

[MrPippin66]

This is primary for the use cases where we expressly have thin-provisioning managed on enterprise SAN storage.

Thin-on-thin is generally not a desirable solution for various reasons, but complicates storage reporting when both are active.

I would request the option to have a storage pool designated as either thick or thin provisioned, though I can understand the issues that might arise with snapshots.

And even though disabling overprivisioning solves some issues, I'd rather have the option of thin-provisioning being completely delegated to the back-end storage subsystem.