Wait-free stream oriented migration based storage

摘要

Embodiments of the invention relate to systematic migration of data. Data is streamed to data storage and stored in a virtual storage device (VSD). Stored data is systematically migrated from the VSD to a higher density VSD, while streaming of data is also switched to the higher density VSD. Source and target data extents are maintained and merged upon completion of the data migration, together with linking the streamed data blocks with the migrated data blocks in the order presented in the input stream.

主权项

1. A method for managing streaming of data comprising:
organizing two or more data virtual storage devices (VSDs) in a first orbit in order of storage density; streaming an input stream of data in an uninterrupted manner from a source to a first VSD in the first orbit, and storing the streamed data in the first VSD; synchronizing movement of the input stream of data from the first VSD to a second VSD in the first orbit, including re-directing the input stream of data from the source to the second VSD, the second VSD replacing the first VSD as a receiver of the input stream of data, concurrently migrating data from the first VSD to the second VSD and draining data from the input stream at the first VSD into at least a final drained data block in the first VSD, wherein the directed input stream of data occurs in the streamed input stream after the final drained data block, and migrating the drained data stored in the first VSD to the second VSD; maintaining a source data extent at the first VSD to support transmission before migration, and maintaining separate receiving and target data extents at the second VSD, the receiving data extent to support migration of the drained data from the first VSD and the target data extent to support transmission of the directed data; and merging the directed data with the migrated drained data in the second VSD upon completion of the migrating of the drained data, including linking a final block of the receiving data extent of the second VSD, including the final drained data block, with a first block of the target data extent at the second VSD.