We can export an virtual volume (zvol) on TrueNas, thanks to the iSCSI protocol.

Storage

Create a pool

Create a zvol from the pool

Sharing / Block/Shars (iscsi)

Target Global Configuration: Modify iqn if necessary

Portals: Add a portal with IP 0.0.0.0

Initiators Groups: Add a initiator with feature of “Allow All initiators”

Authorized Access: No modification

Targets: Add a target with the above portal id, initiator id

Extents: Add a extent with created pool/zvol

Associated Targets: Add an associated target with created target and extent

Services

Launch iscsi service, and start it automaticlly