Andreas Wrede wrote:

> If I detach both fibre channels, tha machine boots fine:

...

> I then can connect the XServe RAID controllers and run
>
> # scsictl /dev/scsibus0 scan any any
> sd2 at scsibus0 target 0 lun 0: <APPLE, Xserve RAID, 1.21> disk fixed
> sd2: 1035 GB, 132522 cyl, 128 head, 128 sec, 512 bytes/sect x  
> 2171240448 sectors

...

> sd2 and sd3 now work as expected - disklabel, newfs, mount and  
> read/write without further error messages from the controller.
>
The above procedure was confirmed on my system as well.

> I did experience a hard lock-up of the system during a large write  
> operation to the filesystem on sd2. I could not even enter the  debugger.

I've seen this happen also [probe(...)], but it was during kernel bootup.

Regards,
Thomas