On Mon, 2012-10-08 at 19:18 -0400, Brian J. Murrell wrote: > Just to followup here on a bit of digging I've been doing... > > The only place in the configfs tree that I can anything that resembles > the value that "scsi_id -g" on the initiator returns is in: > > /sys/kernel/config/target/core/*/*/wwn/vpd_assoc_logical_unit, for example: > > T10 VPD Identifier Association: addressed logical unit > T10 VPD Identifier Type: NAA > T10 VPD Binary Device Identifier: 360014058da4cbf2d90f3d4404d962ed8 > T10 VPD Identifier Association: addressed logical unit > T10 VPD Identifier Type: T10 Vendor ID based > T10 VPD ASCII Device Identifier: LIO-ORG > > I'm guessing that I cannot set the contents of this file though, can I? When I try I get: > > # cat /sys/kernel/config/target/core/iblock_2/sdc/wwn/vpd_assoc_logical_unit >/tmp/foo > # sed -i -e 's/360014058da4cbf2d90f3d4404d962ed8/wc35_sda/' /tmp/foo > # cat > /sys/kernel/config/target/core/iblock_2/sdc/wwn/vpd_assoc_logical_unit </tmp/foo > cat: write error: Function not implemented > That is correct, because the IEEE NAA Registered Extended Device Identifier is required to be in a specific format as per >= SPC-3 standards. The Unit Serial Number (that the above 360001405 prefixed IEEE NAA Registered Extended Device Identifier is based upon) is implementation dependent, and does not define a specific format other than the value needs to be world wide unique. > Ultimately I am trying to achieve what the following does with the tgtd > iSCSI target: > > <target iqn.2008-09.wc35:server.target1> > <direct-store /dev/sda> > scsi_id wc35_sda > </direct-store> > </target> > > When I give that configuration to tgtd on the initiator, scsi_id -g > returns "wc35_sda". > So we hard-code the prefix for the IEEE NAA Registered Extended Device Identifier in target kernel code to follow what SCSI clients expect for this specific type of EVPD=0x83 designator. We do not allow target-mode user-space code to set this value to a format containing a value that SCSI clients do not expect. Using a non world-wide unique value for the one value that initiators depend on as being world-wide queue is a *bad* idea. --nab -- To unsubscribe from this list: send the line "unsubscribe target-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
