I know that. But CoW does cover a few points raised by the previous poster.
> ZFS has deduplication as an optional feature, which is implemented as a content-addressable store of filesystem blocks. In contrast to e.g. git the content-addressable aspect is an implementation detail that is not exposed to users.
I know what dedup is and how ZFS utilises it (I've been running ZFS for about 8 years now - I'm quite familiar with it).
If you read my post again, you'll see I was discussing two separate points: 1) that CoW file systems do provide the pointer-like methods the former commenter raised. And 2) deduping isn't free.
What you're arguing with me is semantics and if you read the former post again, you'll understand why I chose the language I chose.
ZFS has deduplication as an optional feature, which is implemented as a content-addressable store of filesystem blocks. In contrast to e.g. git the content-addressable aspect is an implementation detail that is not exposed to users.
http://blogs.sun.com/bonwick/entry/zfs_dedup