A resilient filesystem

– Stable filesystem bookkeeping information should be replicated throughout the disk (such as ext’s backup superblocks).
– File UUID is updated for each file chunk whenever a new block is written.
– All file chunks should be tagged with metadata such as name, MIME type, and UUID, so that corrupted pointers do not prevent the file data from being located with a sequential scan.
– Each file chunk, as well as the entire file, has an embedded CRC that can be used in recovery as well as in detecting hardware (CPU, memory and/or disk subsystem) failure on the fly if enabled.
– User can choose the amount of parity redundancy.
– Data should be striped such that physical failure events are minimized by the parity information. Seek time profiling can be used to automatically determine the striping characteristics. This also ensures that a sequential overwrite does not lead to catastrophe.
– Directories point to files by UUID as well as by inode. Then directories can be reconstructed in a sequential scan.

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