By adding this command you can recreate the oplog without as much down time; no need for a shutdown – it can just go into recovery mode, drop the existing oplog, create the new one, and continue. It could copy the old data over if it is growing, but I think that could be a future improvement.

The other, and probably better, option would be to put the oplogSize in the replset config for each node. Then you can just reconfigure a set to change the oplog;you would want to be careful not to do them all at the same time as it could take down your rs.