Dealing with Driver Failures in the Storage Stack

This work augments MINIX 3´s failure-resilience mechanisms with novel disk-driver recovery strategies and guaranteed file-system data integrity. We propose a flexible filter-driver framework that operates transparently to both the file system and the disk driver and enforces different protection strategies. The filter uses checksumming and mirroring in order to achieve end-to-end integrity and provide hard guarantees for detection of silent data corruption and recovery of lost data. In addition, the filter uses semantic information about the driver´s working in order to verify correct operation and proactively replace the driver if an anomaly is detected. We evaluated our design through a series of experiments on a prototype implementation: application-level benchmarks show modest performance overhead of 0-28% and software-implemented fault-injection (SWIFI) testing demonstrates the filter´s ability to detect and transparently recover from both data-integrity problems and driver-protocol violations.