Patent ID: 8266191

Claim:
A method, comprising: setting a fractional reserve percentage for an overwrite reserve space of a data container operatively connected to a storage system to a rate of change of data between generation of persistent consistency point images (PCPIs); receiving a write operation at the storage system and determining by a processor of the storage system whether the write operation is directed to a non-reserved data object, the write operation requiring a first amount of space for storage in the data container, the data container comprising an amount of free space; in response to determining that the write operation is directed to the non-reserved data object, determining by the processor whether the data container has sufficient space for the storage system to perform the write operation if the first amount of space required for storage in the data container is less than the amount of free space minus the fractional reserve percentage multiplied by an amount of the overwrite reserve space; and in response to determining that the data container has sufficient space, performing the write operation.