Hi!
I heard someone was working with implementing Fletcher checksums in
softraid.
Do you know any updates on this?
Fletcher checksums are how OpenBSD would guarantee that the data you
read from disk actually has integrity. What makes it different from
traditional checksumming is that it not only guarantees that a
sector/block of data read has integrity within itself, but also that it
actually belonged in the place on the disk that it was read from.
This is of particular importance when having sensitive information on
disks with sector mapping, like all SSD:s (and even magnet disks, or??)
have, which can break down.
For this reason, with ordinary filesystems, reading file contents could
give you just about any data that's anywhere on the disk, while a
Fletcher-based disk would give you a read error.
So it's really like a night and day difference.
https://en.wikipedia.org/wiki/Fletcher%27s_checksum
Thanks!
Tinker
