On Fri, Oct 23, 2009 at 06:55:41PM -0500, Tim Cook wrote:
> So, from what I gather, even though the documentation appears to state
> otherwise, default checksums have been changed to SHA256. Making that
> assumption, I have two questions.
That's false. The default checksum has changed from fletcher2 to fletcher4
that is to say, the definition of the value of 'on' has changed.
> First, is the default updated from fletcher2 to SHA256 automatically for a
> pool that was created with an older version of zfs and then upgraded to the
> latest? Second, would all of the blocks be re-checksummed with a zfs
> send/receive on the receiving side?
As with all property changes, new writes get the new properties. Old data
is not rewritten.
Adam Leventhal, Fishworks http://blogs.sun.com/ahl
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