Patent attributes
One aspect is directed to a method for performing data migration from a first volume to a second volume while allowing a write operation to be performed on the first volume during the act of migrating. Another aspect is a method and apparatus that stores, in a persistent manner, state information indicating a portion of the first volume successfully copied to the second volume. Another aspect is a method and apparatus for migrating data from a first volume to a second volume, and resuming, after an interruption of the migration, copying data from the first volume to the second volume without starting from the beginning of the data. Another aspect is a method and apparatus for migrating to data from a first to a second volume, receiving an access request directed to the first volume from an application that stores data on the first volume, and redirecting the access request to the second volume without having to reconfigure the application that accesses data on the first volume.
