OK, latest in a loooong trail of errors with no information. I've finally gotten a new BE created on another drive, run liveupgrade on it to bring it from sol10u3 to sol10u8
I luactivate sol10u8
lustatus shows the sol10u8 as the active one
init 6
system just starts into 10u3 again.
I'm pasting in a lot of information, sorry, but trying to forestall the 10 messages asking for the info 
root@plato: console: -> lustatus
Boot Environment Is Active Active Can Copy
Name Complete Now On Reboot Delete Status
-------------------------- -------- ------ --------- ------ ----------
sol10u3 yes yes yes no -
sol10u8 yes no no yes -
/
root@plato: console: -> luactivate sol10u8
**********************************************************************
The target boot environment has been activated. It will be used when you
reboot. NOTE: You MUST NOT USE the reboot, halt, or uadmin commands. You
MUST USE either the init or the shutdown command when you reboot. If you
do not use either init or shutdown, the system will not boot using the
target BE.
**********************************************************************
In case of a failure while booting to the target BE, the following process
needs to be followed to fallback to the currently working boot environment:
1. Enter the PROM monitor (ok prompt).
2. Change the boot device back to the original boot environment by typing:
setenv boot-device
/sbus@2,0/SUNW,socal@d,10000/sf@0,0/ssd@w21000004cf0a71a9,0:a
3. Boot to the original boot environment by typing:
boot
**********************************************************************
Modifying boot archive service
Activation of boot environment <sol10u8> successful.
/
root@plato: console: -> lustatus
Boot Environment Is Active Active Can Copy
Name Complete Now On Reboot Delete Status
-------------------------- -------- ------ --------- ------ ----------
sol10u3 yes yes no no -
sol10u8 yes no yes no -
/
root@plato: console: -> lufslist sol10u8
boot environment name: sol10u8
This boot environment will be active on next system boot.
Filesystem fstype device size Mounted on Mount Options
----------------------- -------- ------------ ------------------- --------------
/dev/dsk/c0t0d0s1 swap 537997312 - -
/dev/dsk/c0t2d0s0 ufs 6443905024 / -
/dev/dsk/c0t2d0s1 ufs 5370322944 /usr -
/dev/dsk/c0t0d0s7 ufs 12069957632 /export/home -
/
root@plato: console: -> mount
/ on /dev/dsk/c0t0d0s0 read/write/setuid/devices/intr/largefiles/logging/xattr/onerror=panic/dev=1d80008 on Tue Apr 20 13:34:15 2010
/devices on /devices read/write/setuid/devices/dev=4b80000 on Tue Apr 20 13:33:58 2010
/system/contract on ctfs read/write/setuid/devices/dev=4bc0001 on Tue Apr 20 13:33:58 2010
/proc on proc read/write/setuid/devices/dev=4c00000 on Tue Apr 20 13:33:58 2010
/etc/mnttab on mnttab read/write/setuid/devices/dev=4c40001 on Tue Apr 20 13:33:58 2010
/etc/svc/volatile on swap read/write/setuid/devices/xattr/dev=4c80001 on Tue Apr 20 13:33:58 2010
/system/object on objfs read/write/setuid/devices/dev=4cc0001 on Tue Apr 20 13:33:58 2010
/dev/fd on fd read/write/setuid/devices/dev=4e40001 on Tue Apr 20 13:34:15 2010
/tmp on swap read/write/setuid/devices/xattr/dev=4c80002 on Tue Apr 20 13:34:17 2010
/var/run on swap read/write/setuid/devices/xattr/dev=4c80003 on Tue Apr 20 13:34:17 2010
/export/home on /dev/dsk/c0t0d0s7 read/write/setuid/devices/intr/largefiles/logging/xattr/onerror=panic/dev=1d8000f on Tue Apr 20 13:34:21 2010
/
root@plato: console: -> shutdown -y -i6
Shutdown started. Tue Apr 20 14:26:18 EDT 2010
Broadcast Message from root (console) on plato.???.com Tue Apr 20 14:26:18...
The system plato.???.com will be shut down in 1 minute
showmount: plato.???.com: RPC: Program not registered
Broadcast Message from root (console) on plato.dmc.org Tue Apr 20 14:26:49...
The system plato.???.com will be shut down in 30 seconds
showmount: plato.???.com: RPC: Program not registered
Broadcast Message from root (console) on plato.dmc.org Tue Apr 20 14:27:09...
THE SYSTEM plato.???.com IS BEING SHUT DOWN NOW ! ! !
Log off now or risk your files being damaged
showmount: plato.???.com: RPC: Program not registered
Changing to init state 6 - please wait
/
root@plato: console: -> svc.startd: The system is coming down. Please wait.
svc.startd: 83 system services are now being stopped.
svc.startd: The system is down.
syncing file systems... done
rebooting...
Resetting...
Software Power ON
Clock board TOD does not match TOD on any IO board.
screen not found.
Can't open input device.
Keyboard not present. Using ttya for input and output.
Clock board TOD does not match TOD on any IO board.
5-slot Sun Enterprise E3500, No Keyboard
OpenBoot 3.2.29, 4096 MB memory installed, Serial #13310463.
Copyright 2001 Sun Microsystems, Inc. All rights reserved
Ethernet address 8:0:20:cb:19:ff, Host ID: 80cb19ff.
Rebooting with command: boot
Boot device: /sbus@2,0/SUNW,socal@d,10000/sf@0,0/ssd@w21000004cf0a71a9,0:a File and args:
SunOS Release 5.10 Version Generic_120011-14 64-bit
Copyright 1983-2007 Sun Microsystems, Inc. All rights reserved.
Use is subject to license terms.
Hostname: plato.???.com
LDAP domain name is ???.com
checking ufs filesystems
/dev/rdsk/c0t0d0s7: is logging.
plato.???.com console login: root
Password:
Last login: Tue Apr 20 14:23:00 on console
Sun Microsystems Inc. SunOS 5.10 Generic January 2005
# lustatus
Boot Environment Is Active Active Can Copy
Name Complete Now On Reboot Delete Status
-------------------------- -------- ------ --------- ------ ----------
sol10u3 yes yes yes no -
sol10u8 yes no no yes -
#
root@plato: pts/1: -> lufslist sol10u8
boot environment name: sol10u8
Filesystem fstype device size Mounted on Mount Options
----------------------- -------- ------------ ------------------- --------------
/dev/dsk/c0t0d0s1 swap 537997312 - -
/dev/dsk/c0t2d0s0 ufs 6443905024 / -
/dev/dsk/c0t2d0s1 ufs 5370322944 /usr -
/dev/dsk/c0t0d0s7 ufs 12069957632 /export/home -
---------- Post updated at 04:03 PM ---------- Previous update was at 03:43 PM ----------
also, fyi,
diag-switch? false true
in case anyone wonders if it's set to true, it's not 