Those of you who have been following the lists, the bug trackers or Planet OpenSolaris know this already, but for the rest of you, Sun’s ZFS filesystem has just seen inline dedupe support merged into OpenSolaris trunk, presumably to be appearing in the next major OS release.

Jeff Bonwick has, as always, a very detailed blog entry about it, but here’s the only part you really need to know:

If you have a storage pool named ‘tank’ and you want to use dedup, just type this:

zfs set dedup=on tank

That’s it.

Just as simple as you would have imagined, given how easy everything else is in ZFS and OpenSolaris.

ZFS’s implementation is pretty neat. The filesystem was already pretty well-tuned for deduplication because ZFS has always kept end-to-end checksums of data in the first place to ensure the integrity of all data on the system. Now those checksums just happen to be used for something other than ensuring data integrity.