Why yes, it is possible to build an active/passive ZFS-based cluster using shared DAS and multipath SAS.
Details at: https://github.com/ewwhite/zfs-ha/wiki
The key to this high-availability storage design is a shared SAS-attached storage enclosure, or JBOD. While it's not shared-nothing, this can be a useful way of bringing higher availability to a storage setup that can scale vertically.
To complement the shared JBOD enclosure, we need two servers (head nodes or controllers) to provide client connectivity and compute/RAM resources for the ZFS array.
The servers and JBOD enclosure should be arranged in a SAS cabling ring topology.
This can scale using more enclosures...