On: SnapRAID

[leetnewb]

Greyhole is a clever pooling strategy on an arbitrary set of drives (comparable to MergerFS). SnapRAID is a parity construction strategy on an arbitrary set of drives, and has the side effect of being able to detect and correct bitrot in data. It is pretty common to pair MergerFS with SnapRAID.

[brokenmachine → leetnewb]

Can you not scrub the data with greyhole? That's a pretty big difference if it doesn't.

A big part of snapraid is you regularly do a scrub, and it checks the blocks for errors, which could also alert you to a failing drive.

By default I think it checks 10% of the array every time.

[leetnewb → brokenmachine]

It looks like greyhole added a checksum checksum verification feature (see line 90 here: https://github.com/gboudreau/Greyhole/blob/master/USAGE). I don't know whether it offers the ability to heal bad copies from good.