Tom Reinhart wrote:
Anyone with serious need for data integrity already uses RAID, so why
add brand new complexity for a solved problem?
RAID is great at recovering data, but not detecting errors. File system
can detect errors with checksum. What is missing is an API between
layers for filesystem to say "this sector is bad, go rebuild it."
Actually we dont need a special API: kernel should warn and recommend
running fsck, which scans the whole tree and handles blocks with bad
checksums.
This seems like a much more simple and useful thing than adding ECC into
the filesystem itself.
checksumming is _not_ much more easy then ecc-ing from implementation
standpoint, however it would be nice, if some part of errors will get
fixed without massive surgery performed by fsck
How about we switch to ecc, which would help with bit rot not sector
loss?
Interesting aspect.
Yes, we can implement ECC as a special crypto transform that inflates
data. As I mentioned earlier, it is possible via translation of key
offsets with scale factor > 1.
Of course, it is better then nothing, but anyway meta-data remains
ecc-unprotected, and, hence, robustness is not increased..
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