I must have a problem...
I made theses searchs:
SME Server kernel rotation
SME server kernel backup rotation
SME server old kernel backup rotation
SME server old kernel backup rotation upgrade
SME server kernel backup upgrade
I wasted lot of more than 5 sec... And don't have the answer yet...
When you posted, I think " damned, he's right..."
but I must admit... I must googling wrong, can you give me 5s more?...