What is the effect of adding additional storage while the cluster is in restriping mode?

[Eyob]

I took one of the storage from the cluster to change the battery, but I got an error message that the "This cluster is Over-provisioned and Full.  Writes to thinly provisioned volumes and snapshots in this cluster will fail. Take action now to reduce the space utilization in the cluster. Possible actions include:  delete volumes and snapshots, reduce snapshot retention, add nodes to the storage cluster, use thinly provisioned volumes, move volumes to other clusters, etc."

So is it possible to add additional node(storage) to the cluster while it's restriping?  Does it have an effect since it holds all live servers on it?