Certainly I have a FAS2020 as well (as well as a V3210) and I'm having the same issue with all of them. I'm sure I'm just missing a step, but here's the output of those commands:
fas2220> igroup show
HBSS (iSCSI) (ostype: windows):
iqn.1991-05.com.microsoft (not logged in)
iqn.1991-05.com.microsoft:winslq3r2tam1v (not logged in)
fas2220> lun show -m
LUN path Mapped to LUN ID Protocol
-----------------------------------------------------------------------
/vol/hbss2_vol/hbss2 HBSS 0 iSCSI
/vol/hbss3_vol/hbss3 HBSS 2 iSCSI
/vol/hbss_vol/hbss1 HBSS 1 iSCSI