when booting off powerpath fails

after spending some time baffling over the fujitsu machine resetting itself
i sent a stop-A
and baffled some more, made some errors... none fatal.

then I remembered that powerpath has this problem. Asked CVG.
what needs to be done is
1. boot from local disk
2. mount the power device on /mnt
3. edit its vfstab: comment out the emcpower entry for root disk, uncomment its c#t#d#s# entry
3. edit its /etc/system; comment out the rootdev:/pseudo/emcp@0:a,blk entry
4. boot up; should come up with the /dev/dsk/c#t#d#s# as root
5. edit vfstab, put emcpower back as root
6. edit /etc/system: uncomment the rootdev entry
7. reboot