oracle update on Guest hung on all Guest systems

[vandevoort]

HPUX 11.31 (0909) 6 with Virtual Guests HPVM4.1 systems (HP-UX 11.31 in 0909)
Unfortunately I was not present at that time occurred. but last week, one of the guest systems a oracle update ran 10R2 to 11R2,
during update the guest system hang, but other guests had also performance problems (hang) until the Guest system on which the upgrade was running forced ( TOC) rebooted.
It is one of a Npar Superdome, with 8 CPUs. including 6 guest. Systems running test system on which the update ran was created as a 4 vCPU entitlement default (10:100) 5 other guests each have a guest created 1 vCPU with one Guest never started and entitlement of these Guests also standard (10:100), looked at the hanging one that upgrade Host over 400% CPU capacity used on the host CPU 455% (more than 4 CPUs? memeory did not seem to be a issue within top .
These are all (host and Gust) HP-UX 11.31 and HPVM4.1 (0909).
Any Idea? unfortunately we cannot reproduce this ??? the host swap was smaller than the amount of memory , I Requested to add swap Space up to amount of memory plus 4GB , they did this , but still one time the upgrade system hung the whole Host ..