[callahan]

All SGI systems have the controller at SCSI ID 0. If you have another device at this ID (which your setup does), you will get many errors. Customarily the primary system disk is at ID 1 (although you can change the boot location environment variable) and a CDROM is at ID 4.

You can find my SCSI2SD settings on my GitHub, which have been tested on an Indy, Octane, Indigo2 and Iris Indigo. The most recent firmware, 6.3.1, seems to work fine.

https://github.com/callahan-44/sgivfo

Also, if you're planning on using those CDROMs to mount SGI EFS images, I believe you'll need to set the block size to 512.