Restoring data, without suspending access to the data for the entire time that the data is being restored. Access is suspended only while a portion of the data is restored, before access to all of the data is permitted. A driver virtualizes any remaining unrestored data. To accomplish this, the driver maintains a list of data yet to be restored. If a request to read a portion of the data is then received, and the requested portion is on the list, the driver restores the requested portion before permitting the read request to be fulfilled. The restored portion is then removed from the list of unrestored data. If a request to write a portion of the data is received, the write is permitted, and the location just written to is removed from the list without restoring.