A method is provided for a data storage system to move data from a source logical disk (LD) region to a target LD region while the data storage system remains online to a host. The method includes determining if a region move will create excessive load so the data storage system appears offline to the host. If not, the method includes causing writes to the source LD region to be mirrored to the target LD region, causing data in the source LD region to be copied to the target LD region, blocking reads and writes to the data storage system, and flushing dirty cache in the data storage system. If flushing the dirty cache is fast so the data storage system appears online to the host, the method includes updating mappings of the virtual volume to the LD regions and resuming the reads and writes to the data storage system.
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims benefit of U.S. Provisional Application No. 60/680,721, entitled "Region Mover," which was filed on May 13, 2005 and is incorporated herein by reference. This application is related to U.S. patent application Ser. No. 11/269,024, entitled "Region Mover Applications," which is filed concurrently, commonly assigned, and incorporated herein by reference.
