250 million items per Vault Store

Hi

Happy New Year! ;o)

So I've read that it's not recommended to have more than 250 million items in a single Vault Store..... Does thia mean that if I've designing an Exchange archiving solution for a large busy environment that may journal close to a million items a day after about 250 days (approx 8 months) I need to create a new vault store? I have 4 journal mailboxes so I guess an option is to create a separate vault store per journal mailbox so that will 'spread' the items and hence lengthen the time before I hit this suggested ceiling.

cheers

KL