A method for safely sharing access to a volume is disclosed. In one embodiment, such a method includes notifying a storage system that a volume on the storage system is in use by a first host system. The method stores, on the storage system, a first indicator indicating the volume is in use by the first host system. When the storage system receives an I/O request from a second host system to access data on the volume, the storage system reads the first indicator to determine that the volume is in use by the first host system. The storage system may then reject the I/O request from the second host system as a result of the first indicator. A corresponding system and computer program product are also disclosed.