From: sandip s. <san...@gm...> - 2007-06-27 15:04:42
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Hi Guys, I was looking at the SCST code path to see if it will support more than 256 LUNs. Looking at the report_luns_local code path, i understand that we support only 512 luns right now, because we are not supporting SG handling in that function. Now when i went through the SPC4 docs, i understand that to support more than 256 LUNS we need to use flat space lun addressing. I see that the scst_lun_unpack func, which is called from the rx code path, does differentiate between the LUN addressing methods. But what i fail to understand is that, how does the initiator understand what addressing method to use. When SCST replies to the report_lun_command it just returns the lun id as they are stored in the acg_dev->lun, which are 0, 1, ... So do we have to change the scst_report_luns_local code to change the lun numbers greater than 256. ie. for lun number > 256 we will have to set the 6th and 7th bits as "01" ? I have a qla2340 card on both the initiator and target. I also went through the BIOS settings for qlogic which had a limit of 255 LUNS on a device. So does that mean that the lun id interpretation will be done at the FC level rather than the SCSI layer ? Also i am interested in knowing whether SCST is planning to support multiple target devices. i.e. can we have some changes so that the intiator sees multiple SCSI target devices rather than a single. Thanks in advance for your help. Sandip -- What We Do In Life Echoes In Eternity. |