9.1 SunOS 4.1.X
# Support for the SCSI-2 host adapter with 2 disks and 1 1/4" tape
# on the first SCSI controller, 2 disks and 1 1/4" tape on the second
# SCSI controller, 2 embedded SCSI disks, and a CD-ROM drive.
controller sc0 at vme24d16 ? csr 0x200000 priority 2 vector scintr 0x40
tape st0 at sc0 drive 040 flags 1
tape st1 at sc0 drive 050 flags 1
disk sr0 at sc0 drive 060 flags 2
disk sd0 at sc0 drive 000 flags 0
disk sd1 at sc0 drive 001 flags 0
disk sd2 at sc0 drive 010 flags 0
disk sd3 at sc0 drive 011 flags 0
disk sd4 at sc0 drive 020 flags 0
disk sd6 at sc0 drive 030 flags 0
where the our example CDROM drive, sr0, has a target ID of 6 and an LUN of 0, or 060. This device would then be referenced by the SCSI Hex # of 30, i.e.:
target ID (6) * 8 + LUN (0) = 4810 = 3016
So you would boot from second file on this device as:
sd(0,30,1)
SPARCstation (Sun4c) devices are treated slightly differently. The internal (supplied) disk is target 3. So to avoid confusion (?) they remapped the target device numbers, as follows.
Sun3/Sun3x/Sun4 Sun4c
Target 3 sd6Ūsd(0,18,0) sd0Ūsd(0,0,0)
Target 1 sd2Ūsd(0,8,0) sd1Ūsd(0,1,0)
Target 2 sd4Ūsd(0,10,0) sd2Ūsd(0,2,0)
Target 0 sd0Ūsd(0,0,0) sd3Ūsd(0,3,0)
The NVRAM on the CPU board is used to re-map the target SCSI ID numbers. The ordering of the targets is set with the parameter sd-targets, i.e.:
sd-targets 3 1 2 0 4 5 6 7
The Sun4c GENERIC kernel configuration file then has different entries to describe the attached peripherals, i.e.:
# The following section describes SCSI device unit assignments.
scsibus0 at esp # declare first scsi bus
disk sd0 at scsibus0 target 3 lun 0 # first hard SCSI disk
disk sd1 at scsibus0 target 1 lun 0 # second hard SCSI disk
disk sd2 at scsibus0 target 2 lun 0 # third hard SCSI disk
disk sd3 at scsibus0 target 0 lun 0 # fourth hard SCSI disk
tape st0 at scsibus0 target 4 lun 0 # first SCSI tape
tape st1 at scsibus0 target 5 lun 0 # second SCSI tape
disk sr0 at scsibus0 target 6 lun 0 # CD-ROM device
Sun doesn't support mixing embedded and non-embedded SCSI devices on the same host. Sometimes it works, and sometimes it doesn't. If it doesn't work, don't expect to get any help from Sun.
The SCSI bus must be terminated and this termination should be at the end of the bus line. The maximum length of all the SCSI cables, including internal cabling at the devices, is 6 meters.