Setup Exchange 2013 Archiving

All,

We are planing to migrate Exchange mailbox to 2013 and consider to enable archiving on Exchange. I have question about it,

1. If I enable archiving function, do I need to separate Exchange mailbox Server for this purpose ?

2. Can I use DAG with archiving database mailbox ?

3. For DAG Sizing storage, it recommended mailbox database not larger than 2TB, right ? And Standalone, it recomended size is 200GB ? I want someone can explan more for this ?

thanks

Keith