On Wed, Jul 19, 2006 at 12:38:01PM +0800, Darren Reed wrote: > > Of course this can change (grow) in the future if the ZFS version number > changes? >
Possibly. But it will be difficult. Unlike current version upgrades, such a change would require rewriting every block (because each block isn't versioned individually). This would necessitate an offline data upgrade, which is really nasty and something we try to avoid at all costs. Another possibility is to use the block birth time and some pool-wide metadata to determine when an upgrade took place, and then decode older versions appropriately. This avoids the offline data migration, but adds more complexity elsewhere (and a tax from now and forever whenever decoding a block pointer). - Eric -- Eric Schrock, Solaris Kernel Development http://blogs.sun.com/eschrock _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
