If an operation acquired a volume and a second operation waits for that same volume, the first operation does not wait to acquire any other volumes. If the first operation was allowed to wait for another volume, a deadlock could occur.
Server operations continue, volume acquisition may be tried again, including attempts to mount scratch tapes, but the server operation does not wait to acquire the volume.
If the server operation succeeds, no action is required. However, if the operation fails, you need to supply more scratch tapes to the storage pool.