Start-up problems with sandbox

[badlydrawnboy]

Maybe that isn't the most accurate subject title, but I couldn't think of a better one. What's happening is that in spite of the fact that I have chosen the sandbox as my start-up disk in the start-up disk preference pane, my Mac Pro will frequently start-up with my full volume when I restart the computer.

For example, if I use Disk Utility or Cocktail to run maintenance and then restart, it will often (maybe always?) restart to the full volume (which is an internal 750x2 RAID 0).

Does this have something to do with the physical positioning of the drives in the computer? That never seemed to be an issue in the past. I can't move them around now, can I, with the RAID already configured?

Or does this have something to do with the sandbox?

[dnanian]

They're both internal drives, and it *sometimes* starts from the Sandbox?

[badlydrawnboy]

Yeah, they're both internal drives. The full volume is a 750GBx2 RAID0 and the sandbox is a 74GB Raptor. If memory serves the two drives that make up the full volume RAID are in positions 2 & 3, and the sandbox drive is in position 4.

The computer will start up with the sandbox when I explicitly select it in the startup disk preference pane, and occasionally when I simply restart the computer (not exactly sure of specifics here, as I haven't tested rigorously). However, several times in the past two day it has "automatically" (meaning without me doing anything to cause it) started up to the full volume.

[dnanian]

I don't know why that would be, if the sandbox was set as the startup drive and there was no change to it.

[badlydrawnboy]

Yes, it is quite strange and I've never experienced it before.

I will say I'm having PMU issues (waking from sleep for no reason, shutting down/restarting unexpectedly when I wake the computer up from sleep). I wonder if they're not related somehow.

[dnanian]

Might be. I assume you've tried resetting the PRAM?