problem installing 8.2 on Sun Blade 1000

[Marius Strobl]

On Tue, Aug 16, 2011 at 03:31:52PM +0200, Riccardo Veraldi wrote:
> Hello,
> I focused closer to the problem.
> I have 2 internal 18GB SCSI Segate disks and 2 external SCSI HITACHI 
> 140GB disks.
> now if I Remove the external disk cabinet, everything works and FreeBSD 
> install and boot
> from the internal disks.
> 
> After installation if I add the external cabinet with 2 SCSI-III disks 
> at boot the system
> goes kernel panic since it cannot find root on /dev/da0a
> 
> it is like if GEOM confuses the disk and the internal da0 and da1 disks
> are confused with the external disks which are called the same da0 and 
> da1 like the internal disks, this is the problem.
> I checked the SCSI IDs and they are all ok, I renumbered the external 
> SCSI ID disk in the cabinet.
> I Can see disk correctly with probe-scsi-all
> 
> but on boot external disks are recognized as da0 and da1 like the 
> internal disks and system is messed.
> 
> anyone got this problem before ?
> 

If the external and internal disks hang off of different HBAs then which
disk becomes da0 then is not only determined by the ID but also depends on
what HBA is probed first, which FreeBSD does based on the order provided
via the device tree provided by the firmware. If that's the case you
should be able to influence the probe order by changing the slot order in
pcia-probe-list and pcib-probe-list respectively as appropriate in the
PROM boot monitor or using eeprom(8).
Apart from just living with the root filesystem just not being on da0
(besides having a matching /etc/fstab you might also need to set
vfs.root.mountform as appropriate) you should be also do solve this
by wiring da(4) devices to certain IDs on certain busses via hints
(see SCSI DEVICE CONFIGURATION in the MI NOTES) and probably also by
using glabel(8) in order to set labels which then can be used instead
of da(4) devices names.

Marius