QUOTE (Squire)
You didn't ask for it, but I'll give you my personal opinion. It's much easier and safer for a production server to simply lease another Plesk 7.x server, make sure everything is updated, then use Migration Manager to move over all of the domains to the the new location.
Once that's done you can tweak the DNS in the old server so that everything points to the new server. And change the DNS for your nameservers if you're running your own or change all of the domain records so that they point to the new server.
That'll keep you from having any downtime and give you an easy backup plan in case it becomes necessary. Though it does require that you overlap the server leases. I generally try to keep the old server running for a month to let DNS propagation take place.
Thankyou Squire! running a machine in parallel seems a better work around.
Earlier I was thinking of creating a dump of current domains on currently running hard disk and when the machine comes online with this hard disk slaved. I would have run the restore utlities .. but it means more downtime.
thankyou for your comments
Asif