[callahan]

Raion's right. The best disk option for the Octane are surplus 80-pin SCSI disks. Something like this: https://www.ebay.com/itm/Seagate-300GB-U...2309163701

Acard used to make a SCSI-SATA adapter, but they now sell for $1,000+ used. SCSI2SD can't compete with UW SCSI disks and costs far more (see my recent performance post in the hardware section).

I've had good luck with a HP DVD-ROM, like this one: https://www.ebay.com/itm/HP-0950-3398-A-...3156206385 , but as Raion points out it isn't necessary. Copying/installing from a network is normally far faster and easier. I've never actually had to use a CD in any of my SGIs. Note you'll also need an external 5.25" SCSI drive bay, which have gotten very expensive recently.