Failed boot disk, lost iscsi configuration

[thinnetinc]

I have a Isolon NL400 with 36 drive. It is configure with 34 drives in a Dataset Pool. My host are 2 2016 Windows Hyper-V Host. The Boot Drive failed completely and Freenas became inaccessible to all forms of connections. I have it back up and running with a USB boot. I was able to import the pools. I started to rebuild the ISCSI and froze when I got to the Extents. I'm afraid of destroying the data. I thought I used File Extents but looking at the pool it listed as a Dataset. But the Disk I Think need to recover is a ZVOL. So "I'm Guessing" that this one was a Device Extent. That's my issue. I'm Guessing.

If I try to create a Device Extent This is what I see.

If I try to create a File Extent his is what I see

So I'm a little nervous to proceed