Solaris Troubleshooting : how Solaris assigns controller numbers

In this post I am talking about  some of the observations on  how Solaris determines  the controller numbers

Below are 3 common scenarios encountered by customers:
1) A jumpstart is done with nothing but an internal disk and DVD on the system.

• -Assigns cdrom C0
• -Assigns internal fcal disk C1

2) A jumpstart is done with nothing on the system, then a photon(A5000) is added afterwards in slot2.

• -Assigns cdrom C0
• -Assigns internal fcal disk C1
• -Assigns photon C3

*what happened to C2?

3) A jumpstart is done with a photon attached to the system.

• -Assigns cdrom C0
• -Assigns internal fcal disk C2
• -Assigns photon C1

We should understand how the Solaris controller numbers are assigned to the hardware devices.

Controller numbers are assigned in the following order when booting from the net or cdrom to do an initial install of the  Operating System:

1. Onboard CDROM = C0

2. Onboard external SCSI  = C1 (if devices are attached)

3. PCI SCSI or FCAL = C3 through C10 (if devices are attached, assuming max. dual channel cards)

4. Onboard FCAL = C11

If items 2 and 3 don’t exist, then Onboard FCAL = C1

When adding new PCI cards after initial install, the controller numbers will be incrementally assigned from the last controller number.

pcia-probe-list and the pcib-probe-list have no effect on this.

pcia & pcib represents the 2 PCI buses in this example, the 280R platform:

pcib 5       RIO [ ebus, network(eri), usb ]

6       SCSI ( disk(s) & tape(s) connected to internal scsi

1       BBC, mouse, & serial ports,

2       33-Mhz pci slot #2

3       33-Mhz pci slot #3

4       33-Mhz pci slot #4

pcia 4       fcal

1       66-Mhz pci slot #1

Please remember that controller ‘instances’ are only assigned when devices (disks & tapes) are physically attached to the controller.  Once an instance is assigned, that controller is permanently reserved that instance, as indicated by the /etc/path_to_inst file. One suggestion for Jumpstart profiles is to recommend installing the system without any PCI cards or Onboard external SCSI. That way, the Onboard FCAL where OS should be installed is always controller 1, target 0 or 1.