Checksumming blocks? [was Re: the " 'official' point of view" expressed by kernelnewbies.org regarding reiser4 inclusion]

Russell Leighton
2006-08-03T23:22:08Z

If the software (filesystem like ZFS or database like Berkeley DB)
finds a mismatch for a checksum on a block read, then what?

Is there a recovery mechanism, or do you just be happy you know there is
a problem (and go to backup)?

Thx

Matthias Andree wrote:

>Berkeley DB can, since version 4.1 (IIRC), write checksums (newer
>versions document this as SHA1) on its database pages, to detect
>corruptions and writes that were supposed to be atomic but failed
>(because you cannot write 4K or 16K atomically on a disk drive).
>