[eli]

At one point it was a significant bullet point in the list of features being added to OS X Server. It was a big deal. I'm sure he was aware of it.

http://www.zdnet.com/article/apple-announces-zfs-on-snow-leo...

[dlitz]

I used OS X Server in 2008. It had major quality issues that seemed to only get worse with subsequent releases. Several advertised features accessible from the UI didn't work or straight-up broke things. I doubt Jobs paid much attention to it.