Is it possible to expand an existing gluster volume?

I have a hyperconverged environment, and have enough space right now, but I'm going to have to significantly over-provision my environment. The vast majority of our customers are using a small fraction of the amount of space that they are technically allocated, but we still need to make that space available to them.

As a result, I'd like to plan ahead, and go ahead and have a plan to add storage later down the road.

I'd like to plan to shut down each server in the cluster (individually, not at once), add storage, and then bring them back online. Once all 3 are back online with the additional storage, I'd like to expand the gluster volume to use the additional space. Is that possible? How?