Patent attributes
Embodiments of the present invention provide a mechanism by which a server system executing a host application monitors utilization of overwrite reserve space on a volume storing application data. The server system executes space reservation policies to ensure that the volume cannot run out of space due to snapshot creation. In one implementation, the server system initiates deletion of backup datasets stored on the volume if certain criteria provided by a system administrator are met. If deleting backup datasets cannot not stop the volume from running out of space due to continuous snapshot creation, the server system prevents the host application from temporarily issuing I/O requests to the storage system until space is recovered. Preventing the host application from issuing I/O requests, rather than failing I/O requests by the storage system, eliminates undesirable consequences, such as loss of data and the need to perform data recovery.
