DragonFly kernel List (threaded) for 2007-10
Re: HAMMER filesystem update - design document
Francois Tigeot wrote:
On Wed, Oct 10, 2007 at 12:33:45PM -0700, Matthew Dillon wrote:
Ok, here's the final design document that I am now implementing.
Again, I expect most or all of these features to be ready and the
filesystem to be beta-quality by the December release.
Wow, this seems pretty good.
What about data corruption issues ?
Have you thought about implementing some sort of checksumming mechanism ?
We cannot assume hardware to be absolutely reliable. There may be some
silent corruption going on the disk or network layers, etc...
More on this in this article:
Quoting from Matt's announcement:
" All information in a HAMMER filesystem is CRCd to detect corruption."
So the question - if there is one - is 'how good' that check is.
Otherwise, not the fs' job.
It *must* presume a 'generally reliable' environment beyond a certain point.
Error prevention, detection, (possible) correction, and friends more properly
should exist in the storage hardware, I/O, and link layers.
As they do. Or do not.
. .. just as the article you cited points out.... hardware and driver selection
issues, or even suboptimal silicon.