[CentOS] block level changes at the file system level?

>> I think the buzzword you want is dedup.
> dedup works at the file level. Here we're talking about files that are
> highly similar but not identical. I don't want to rewrite an entire file
> that's 99% identical to the new file form, I just want to write a small
> set of changes. I'd use ZFS to keep track of which blocks change over time.
>
> I've been asking around, and it seems this capability doesn't exist
> *anywhere*.

Check this link.

https://blogs.oracle.com/bonwick/entry/zfs_dedup

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*What to dedup: Files, blocks, or bytes?*

Data can be deduplicated at the level of files, blocks, or bytes.
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