Converting an Ultra SPARC 10 from IDE to SCSI

by Jonathan P. Voss

This paper describes how to convert your IDE interfaces to SCSI without having to have a single IDE device to boot from. It is meant to be more of a HOWTO then an example. For this discussion I used the following equipment:

The first and obvious step most likely completed by all of you is to install the equipment physically. I used the Plextor to replace my original 48X cdrom drive that came with the Ultra 10. The same was for the 36GB drive to replace my former 18GB IDE drive.

Once the hardware is physically installed, i.e. SCSI card, cdrom drive, and hard drive, its time to move into the Open Boot modifications. As soon as possible hold down Stop-A to enter the PROM. Our first objective here is to relocate what device it thinks the cdrom is pointing to. To achieve this follow the steps below:

  1. At the ok prompt type: 
    probe-scsi-all

    This will allow us to make sure the system can "see" the devices you just kinstalled. If the list is valid, showing the devices you just installed continue. Other wise you might want to try typing boot -r at the prompt to do a reconfigure boot to pick up your scsi card.

  2. Next at the ok prompt type: 
    show-disks

    Remember after typing probe-scsi-all the locations it spitted out for the devices? With this information you can selection from the list the correct scsi device for your cdrom drive.

  3. Once selected and you've pressed enter to get back to the ok prompt type: 
    nvalias cdrom ^Y

    (^Y denotes CTRL-Y) BEFORE pressing enter amend the @X,0:f to the end of the command onto disks, where X is = to your SCSI target ID that is assigned to your drive.

    Here is an example of what it should look like: 

    /pci@1f,0/pci@1/scsi@3/disk@4,0:f

    Where 4 would be the SCSI ID of the drive. Note that your exact address may vary from the example depending on the hardware being used.

    This will set what the PROM believes as your cdrom drive.

  4. Now its time to switch what it thinks is your hard drive. At the ok prompt type: 
    show-disks

    Now select the correct address for your first hard disk (if you have multiple ones select the address of which one you would like to be your primary.

  5. Repeat step 3 again except using: 
    nvalias disk ^Y

    Then adding the SCSI ID the same way for your first hard drive. If you plan to use more then one hard drive repeat steps 3 and 4, making sure to assign the correct SCSI ID. Assign your hard drives alias name such as "disk" in the following order:


  6. Once the PROM is updated with the new location of the devices it is time to reboot the system. If you plan to install Solaris 8 from a bootable CD type boot cdrom at the ok prompt.

    The computer should reboot and boot your CD.

  7. This step is primarily just a note to correct a common problem when installing new hard disks. When trying to install Solaris and you receive the error "Wrong magic number... " or so on, you do not have a bad disk. Sun hard disks are formatted with a special number at the first part of the disk. If it does not match this number it will spit out a "Wrong magic number..." error. This can easily be corrected:

    If you receive this error the CD will escape to a make shift shell. From this shell you can run the command format, which will allow you to format your hard drive and place the correct magic number at the beginning of the drive. Reboot the machine and you should be set. The Solaris installer will let your re-partition your drive just as you have done in your previous installations and you should be set.

I hope this HOWTO has proven successful for you.

Good Luck...

Addendum by Mike Gerdts

For further help...