First of all I want to thank all who replied. My original questions were;
I have a ss20 with 2 internal drives. Drive one sd0, has SunOs 4.1.4.
Drive two sd1, has Sol 2.5.1. SunOs 4.1.4 is the default drive when
rebooting with no parameters. I'd like to be able to boot up Solaris2
without actually swapping drive locations. On Solaris drive, I've edited
vfstab and mnttab so that any field with'c0t3d0' would be 'c0t1d1'. When
I do 'boot disk1' I'd get the following errors then it returns me to 'ok'.
I tried changing value 'c0t3d0' to 'c0t1d0', did not work. I also tried
booting from Sol2.5.1 cdrom into single user method, I was unable to
mount root partition from disk with Sol. 2.5.1 in /mnt.
A few of you suggested reinstalling Sol2.5.1 directly into sd1, this method
worked. I can now boot Solaris2 by doing 'boot disk1'.
Thank you all again for you time.