Patent ID: 6985995

Claim:
A method for storing a data file in a storage system having a plurality of storage disks, said method comprising: (a) providing a stripe across said plurality of storage disks, said stripe comprising a plurality of data stripe units and a parity stripe unit; (b) storing said data file in a first format consistent with RAID-1 using only a first data stripe unit from said plurality of data stripe units and said parity stripe unit until a size of said data file exceeds an allocated storage space in said first data stripe unit, wherein during step (b) said parity stripe unit maintains a mirrored copy of data contained in said first data stripe unit; and (c) when the size of the data file exceeds said allocated storage space, storing said data file in a second format consistent with RAID-X and inconsistent with RAID-1 using said first data stripe unit, at least one further data stripe unit and the parity stripe unit wherein no rewriting of the data contained in the first data stripe unit occurs when storage of the data file transitions from said first format to said second format, and wherein RAID-X refers to a non-mirrored RAID scheme employing an XOR-based error correcting code.