iSCSI is an IETF standard (RFC 3720) for remote access to block-level
storage.  It can be thought of as similar to NFS, except that an NFS
server exports files; the iSCSI target exports blocks to the iSCSI
initiators, which are the clients.

The NetBSD iSCSI initiator is based on FUSE/ReFUSE, and provides a
portable initiator for any operating system with a FUSE-like
interface.