[dm-devel] Some thoughts about providing data block checksumming for ext4

Darrick J. Wong darrick.wong at oracle.com
Wed Nov 26 23:47:06 UTC 2014


Well, I wrote up a preliminary version of dm-checksum and then
realized that I've pretty much just built a crappier version of
dm-dedupe, but without the dedupe part.  Given that it stores
checksums in a btree which claims to be robust through failures and
gives us automatic deduplication, I wonder if it we could achieve our
aims by modifying dm-dedupe to verify the checksums on the read path?

I guess it would be interesting to see how bad the performance hit is
with the online dedupe part enabled or disabled.  dm-dedupe v2 went
out on the mailing list last August, which I missed. :(

Unless... there's a specific reason nobody mentioned dm-dedupe here?


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