I upgraded to b115 and had the same problem: immediate panic on boot... the panic information stayed on the screen for a small fraction of a second... not long enough to read.
I was able to make the box bootable, but it took a few hours of struggling. My setup is a desktop PC with two 1TB SATA drives. I had b114 installed in a ZFS pool named "rpool"; it was mirrored between both drives. I loaded b115 from scratch... this created a new unmirroed pool named "rpool" on the first disk. A copy of b114 remained on the 2nd disk. When I tried to boot the new b115 installation, I got as far as the grub menu. The first choice in the grub menu resulted in an immediate panic and reboot. The 2nd choice in the grub menu (xvm) also panicked but the panic message stayed on the screen. The main error was something like: cannot mount root on rpool/51 The third choice (failsafe mode) worked fine. It started to become apparent that grub was trying boot the OS on the 2nd disk instead of the first disk. The panic was coming from the old b114 installation. I booted into single user mode and renamed the pool on the 2nd disk. This did not solve the problem. I then destroyed the pool on the 2nd disk (zpool destroy). On the next reboot, the new installation of b115 on the first disk came up cleanly. My guess is that the problem comes from the "findroot" grub function. I think it is incapable of choosing the correct pool if there are two bootable pools. -- This message posted from opensolaris.org
