On Fri, Sep 15, 2006 at 10:55:48AM -0500, Nicolas Williams wrote: > On Fri, Sep 15, 2006 at 09:31:04AM +0100, Ceri Davies wrote: > > On Thu, Sep 14, 2006 at 05:08:18PM -0500, Nicolas Williams wrote: > > > Yes, but the checksum is stored with the pointer. > > > > > > So then, for each file/directory there's a dnode, and that dnode has > > > several block pointers to data blocks or indirect blocks, and indirect > > > blocks have pointers to... and so on. > > > > Does ZFS have block fragments? If so, then updating an unrelated file > > would change the checksum. > > No. It has variable sized blocks.
OK, thanks.
> A block pointer in ZFS is much more than just a block number. Among
> other things a block pointer has the checksum of the block it points to.
> See the on-disk layout document for more info.
I am aware of the block checksum, but haven't got round to reading the
on disk format document yet, hence the question.
> There is no way that updating one file could change another's checksum.
That follows from the non-existence of fragments, sure.
Cheers,
Ceri
--
That must be wonderful! I don't understand it at all.
-- Moliere
pgptLzZIZQJCY.pgp
Description: PGP signature
_______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
