OpenStack Liberty Design Summit

IBM and BDT are experimenting with running Swift on top of file systems with disk and tape integration. The approaches reuse existing disk and tape file systems, and connect them either by using the DMAPI mechanism or by building a virtual file system on top, exposing the resulting file system with disk and tape to Swift. We will explain the approaches and describe how the file systems migrate object data from disk to tape, how the tape data is referenced and how it is recalled back to disk when it is accessed via Swift.

Then we will explain the Swift challenges we encountered when integrating and using the tape, with the main idea to discuss with and learn from the Swift community what could be a proper way to address those challenges. For example, one challenge is performing explicit or asynchronous data management between disk and tape via Swift interface. Another example is achieving a good data collocation on tapes and a proper use of tape drives when scaling the system, which is related to Swift's distribution of objects to partitions.