Notes from the LSF storage track

The day began with a review of request-based multipathing, which is trying to solve the problem that the device mapper operates multipathing way above the block layer and thus has great difficulty getting accurate data from and control of the underlying devices, which are often much lower, way below the block subsystem. The agreed solution to this problem is to implement a request-based layer for multipathing which can sit underneath the block layer and provide a bidirectional conduit to the device mapper above the block layer such that status and event processing of multipath related information can occur much closer to where the actual events are generated…