booting hangs at "Waiting for SCSI devices to settle"

[Matthew Dillon]

:I'm having a really hard time booting one of my machines.  It keeps
:getting stuck at:
:
:Waiting 2 seconds for SCSI devices to settle
:
:I'm able to break to debugger.  Here's what a ps looks like:

    One of the CAM devices is not returning from its XPT_BUS_SCAN
    action.

    You have to find out which one.

:   32 0xda3ba800  -1 00020e80 12/02/01 0xda3cec9c ccb_scan xpt_thrd
:...
:   32 0xc03e2274  -1 00210400 28/01/00 0xda67dd88        - ithread 18
:   32 0xda3bac00  -1 00020e80 12/02/01 0xda6a2c94     idle aic_recovery0
:   32 0xc03e239c  -1 00210400 28/01/00 0xda6f7d88        - ithread 19
:   32 0xda3bad00  -1 00020e80 12/02/01 0xda6fac94     idle aic_recovery1
:   32 0xc03e2024  -1 00210400 28/01/00 0xda722d88        - ithread 16
:...
:
:I have to keep rebooting the machine until it finally decides to work.
:What else can I try?
:..
:--Peter

    We have to figure out which SCSI device is having the problem.  Any
    AHCI or USB stuff plugged in?  Or is the only CAM bus from the AIC
    driver?

						-Matt