Disk storage apparatus and method for converting random writes to sequential writes while retaining physical clustering on disk.

摘要

A high performance disk subsystem is disclosed having a disk write mechanism that provides high throughput for random disk writes by dividing the disks into a data portion and a log portion. A fault-tolerant memory in the disk controller is used to temporarily store data blocks or pages which are written. The updated blocks are sorted in the fault-tolerant memory in accordance with their physical home location on the data portion of the disks. Sorted runs are temporarily written out to the log portion of the disk. In a parallel process, sorted runs are retrieved from the log portion of the disks, merged in the fault-tolerant memory, and written out to their home location on the data portion of the disks, which converts random disk writes to largely sequential I/O while retaining physical clustering of the data on disk.