Patent ID: 8732485

Claim:
A method, comprising: defining a new encryption band with a length that is consistent with a redundant array of inexpensive disks (RAID) parity strip; freeing a working extent in a working stride on the RAID; in an iterative process until each stride in a source band is depleted of data: marking a source extent in a source stride from which to gather data to be re-encrypted; marking parity inconsistent in the working stride in the new encryption band; in a second iterative process until each extent in a source stride is depleted of data: copying the source extent from the source stride to the working extent in the working stride; marking parity consistent in the working stride; assigning the source extent in the source stride as a target extent in a target stride; shrinking the source band from which the source extent was copied by an amount related to an amount of data copied from the source stride to the working stride; expanding the new encryption band by an amount related to the amount of data that has been copied from the source stride to the working stride; copying all data from the working extent to the target extent; marking parity consistent in the target stride; and marking parity inconsistent in the working stride; and freeing the working extent.