摘要 |
METHOD FOR IMPROVING PARTIAL STRIPE WRITE PERFORMANCE IN DISK ARRAY SUBSYSTEMS A method and apparatus for improving disk performance during partial stripe write operations in a computer system having a disk array subsystem utilizing parity fault tolerance technique. When a partial stripe write generation is begun, the method determines if the area or stripe where the write is to occur is unused space in the file system. If not, the partial stripe write operation is performed using a preceding read operation to read the current data and parity information from the disk as would normally be done. However, if the write area is unused space in the file system, then the contents of the data stripe do not need to be preserved. In this instance, the partial stripe write operation can be performed without any preceding read operations. By obviating the necessity of a preceding read operation, much of the performance penalty of doing a partial stripe write in the case where the rest of the data stripe does not need to be preserved is removed. |