This should be a simple one to answer but i cant find it anywhere...
Can i install the update manager database onto the VC database ? or does it have to be a seperate one.
No, it does NOT have to be on a separate database from VirtualCenter--however, that is a best practice. And after my experiences in the past week with Update Manager (I'm fairly new to it) I'd recommend having a separate database. The installer seems to be inconsistent in how it works as I've had a variety of issues that eventually were fixed by an uninstall/reinstall. Unfortunately, each time I do a reinstall and it asks if I want to reinitialize the database I have to say no because it is shared with my VirtualCenter database. I have a feeling that completely starting over on the DB would've more quickly solved some of the issues I've had. So, make it separate if you can and you'll have more flexibility that I do in this environment.
This is an interesting point you raise.
I am implementing at a client site, one of the requests was to use a single database for both VC and UM. Was my first 3.5U2 deployment, and I didn't know if it could be done. We are installing on an Oracle DB rather than SQL, and during the installation of VC, installing VC and UM in the same database is the default option - ie: you don't get a chance to point to a different database for UM, just the one ODBC DSN to point to during installation.
Interesting, as I asked VMware about the option of using a single database (and so did the client) and we were both told "No".