Betriebsverfahren einer Speicherplattenanordnung

摘要

A method for updating data and parity information in a RAID level 4 or 5 disk array employing a read-modify-write (RMW) process for updating data and parity information separates the execution of data read and write operations from the execution of parity read, generation and write operations to permit greater efficiency in the utilization of the drives within the array. The method identifies the disk drives containing the data and parity to be updated and places the proper read and write requests into the I/O queues for the identified data and parity drives, scheduling parity operations; i.e. reading old parity information from the parity drive, generating new parity information and writing the new parity information to the parity drive; for execution when best accommodated in the I/O queue for the parity drive, following the read of old data from the data drive.