Auto boot problem on Sun T2000

Hi All

I have a problem on T2000 server.

bash-3.00# uname -a
SunOS 5.10 aaa Generic_120011-14 sun4v sparc SUNW,Netra-T2000

After the initial solaris installation server failed to boot:

Rebooting with command: boot
Boot device: disk:b  File and args: 
The file just loaded does not appear to be executable.
{0} ok 

So I ve decided to go with:

{0} ok boot disk

It was fine with booting like this! I was a little bit short on time So I couldn't fix it permanently and had to go with the workaround.

Later on when I checked the installation logs:

bash-3.00#
bash-3.00# tail -10 /var/sadm/system/logs/install_log

Customizing system devices
        - Physical devices (/devices)
        - Logical devices (/dev)

Installing boot information
        - Installing boot blocks (c0t1d0s0)
        - Installing boot blocks (/dev/rdsk/c0t1d0s0)
        - Updating system firmware for automatic rebooting
WARNING: Could not update system for automatic rebooting
bash-3.00#
bash-3.00#

What I understand is, I need to change the boot device or auto-boot.
System is running on a live environment now so I have to fix this without interrupting the server.

So with current conditions server will fail to boot If anything goes wrong and If server needs to restart.
My question is, what should I do to prevent this? and what is the safest way to do it without restarting server?

Any help/ideas will be great!

Regards
Oguz

check the devalias.. maybe its pointing to the wrong boot device