partitioned hd for time machine

Hello, Is it possible to use a partitioned ext. hd to back up (via time machine) a dual boot snow leopard/lion set-up in such a way as to have 1 partition recognize and back up only lion when it's being used and another partition do the same for snow leopard? I would like to keep the two separate to avoid potential corruption/compatibility issues. Please explain the process req'd to do this as well (assuming it's possible). Thanks very much, Jeff

Can you please explain a bit more on this dual boot Snow Leopard / Lion setup ?
I don't fully understand your request.

Cheers ... McBie

Haven't done it yet, but I have seen how lion can be installed along with, rather than instead of snow leopard. At start-up, user can opt for mac to boot one or other (each os is installed onto its own partition of internal HD). What I was asking above is how to set up a partitioned ext. HD so that a partition can be assigned to back up (via Time Machine) the corresponding partition of the internal drive, rather than everything at once, thus keeping a lion back up as well as a snow leopard back up separate from each other. If mac booted up in lion, TM makes back up of only lion, etc. Hope that makes sense and thanks very much for the prompt reply, Jeff

All you need to do is create 2 partitions on your backup disk. That way you can have a separate drives for Snow Leopard backups and another one for Lion backups.

Please check if the setup you propose above is not violating the Apple EULA or any other legislation.

Cheers ... McBie

Thanks for the help. No worries w/ any violation-- snow leopard came w/ my mac when purchased and lion was downloaded from app store. Follow up: I currently have ext. back up drive unpartitioned and being used for snow leopard TM. When partitioning the ext. drive, will I need to re-name, re-configure in any way to specify that partition will be exclusively for snow leopard? When I install lion, how will I specify the newly created partition to make TM back ups for lion?