Patent ID: 7636744

Claim:
A method for implementing space reservations in a data container served by a computer data storage system, comprising: (A) setting a fractional reserve percentage; (B) receiving a write operation directed to the data container; (C) determining if the write operation is directed to a reserved file; (D) in response to determining that the write operation is not directed to a reserved file, determining whether the space needed to complete the write operation is less than a space available less a fractional reserve percentage multiplied by an overwrite reserve in the data container; (i) in response to determining that the space needed to complete the write operation is less than the space available less the fractional reserve percentage multiplied by the overwrite reserve in the data container, performing the write operation; and (ii) in response to determining that the space needed to complete the write operation is not less than the space available less the fractional reserve percentage multiplied by an overwrite reserve in the data container, rejecting the write operation; (E) in response to determining that the write operation is directed to a reserved file, determining whether a space needed to complete the write operation is less than a space available in the data container; (i) in response to determining that the space needed to complete the write operation is less than the space available in the data container, performing the write operation; and (ii) in response to determining that the space needed to complete the write operation is not less than the space available in the data container, rejecting the write operation.