after a rescan with esxfg-swisci I get the following message i vmkernel
SCSI: 8021: vmhba40:1:0:1 status = 0/1 0x2 0x8 0x0
WARNING: SCSI: 7916: status No connection, rstatus #c0de00 for vmhba40:1:0. residual R 999, CR 80, ER 3
WARNING: FS3: 4008: Reservation error: No connection
A grep -R -i "oldiscsilun" in /etc shows nothing
BTW: in VI client I was unable to disable the iSCSI initiator (I didn't try it with esxcfg-swisci - at the moment there's a VM running on the storage)