> > Is it possible to "scrub" (check/verify) (the new-) checksums in ext4? > > When e2fsck does a full check, it verifies the contents of all of the > metadata blocks, and this includes verifying all of the checksums. Ok. But that would only when the filesystem is not mounted. Maybe some on-line functionality for doing so would be nice. I'm not totally aware of the filesystem structures in memory/on disk, but reading meta-data from disk which has changes pending in memory/in the journal would give at worst a verify of old(er) data. I don't think this (checking occasional old data) is a bad thing - scrubbing a raid-device/disk doesn't give you the situation for the whole disk(s) in 1 (!) point at time either. If that would be required, then the user could still unmount the filesystem and do a check. > > Also: is it planned to add an option to add checksums to the data as > > well? > That's not currently on the development roadmap; I could imagine > someone deciding to design an extension to ext4 that would do this > probably by storing the checksums in the indirect blocks, but no one > is currently working on it. Would crowdfunding such a feature be an option? E.g. via https://www.catincan.com/ or http://www.kickstarter.com/ On other thing I was thinking of, was a switch that would enable a read-after-write which would verify that the data is indeed on the platters/NAND-chips. (I don't care (too) much about speed - I just want to be really sure my data doesn't get corrupt/lost without investing huge piles of money on a san/nas with remote mirroring etc.). Regards, Folkert van Heusden -- Winnen in de staatsloterij? Check htp://vanheusden.com/sl.php voor alle staatsloterij-uitslag statistieken denkbaar en zelfs ook een paar win-tips! ---------------------------------------------------------------------- Phone: +31-6-41278122, PGP-key: 1F28D8AE, www.vanheusden.com -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
