MULTI-WAY CHECKPOINTS IN A DATA STORAGE SYSTEM

摘要

Certain embodiments of the present invention allow multiple checkpoints to be taken so that multiple versions of the file system, including a working version and at least two checkpoint versions, can be maintained over time. Specifically, at least three "superblock" root structures are used to manage multiple instantiations of the file system. The superb locks are preferably stored in fixed locations within the storage system for easy access, although they may alternatively be stored in other ways. The number of superblocks may be fixed or variable. Other embodiments provide for validation of objects and data structures in a data storage system.