In the downloads section of: http://www.torque.net/sg/sdebug26.html is a beta version of scsi_debug version 1.77 . It simulates a single port of a dual ported SAS disk (with many of the VPD and mode page trimmings). This beta adds an extra parameter: "no_lun_0" which when set to one implements the code suggested by Pat Mansfield in this post: http://marc.theaimsgroup.com/?l=linux-scsi&m=112751597527556&w=2 It also goes into unchartered territory and implements lun 49409 which is the REPORT LUNS well know logical unit. Those folks out there that are paranoid about "specs" will be glad (or perhaps disappointed) that it doesn't break anything. Why do it? Well the spec says that a SCSI target should either implement: - the phantom lun=0 technique, or - the REPORT LUNS well known lu to facilitate lu discovery. This with lk 2.6.14-rc3 : # modprobe scsi_debug no_lun_0=1 max_luns=2 # modprobe sg # cd /sys/class/scsi_host/host0 # echo "- - 49409" > scan # # lsscsi -g [0:0:0:1] disk Linux scsi_debug 0004 /dev/sda /dev/sg0 [0:0:0:49409]wlun Linux scsi_debug 0004 - /dev/sg1 # # sg_luns --decode --select=2 /dev/sg1 Lun list length = 16 which imples 2 lun entries Report luns [select_report=2]: 0001000000000000 Peripheral device addressing: lun=1 c101000000000000 REPORT LUNS well known logical unit Notice that 0:0:0:0 is missing but a trace will show that it did answer an INQUIRY and a REPORT LUNS. The scsi_debug driver needs to set its Scsi_Host::max_luns to 49409 so the "echo" above will work. Perhaps the scan code could be a bit more open minded. Doug Gilbert - : send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
