I have a newly configured EX490. On my MBP, I created a 500GB 'disk' for the backups. I did not initiate any TM backup yet.

On my Mac Mini, I can also see the server. I can go to the Mac folder. I can see the folder from my Mac and it shows as a FILENAME.macbackup file that's 500GB. So it looks like WHS saves the TM's to some kind of file container.

Now, I want to setup a TM backup from my Mini as well. But it seems that it makes me create another Mac disk for each machine. Is this true, do I have to create a different 'container' for each machine I want to backup? I assumed I could put them all into the Mac folder.

Also, my Mini has an existing TM backup w/ 7 months of history. I found that I could do the following to 'move' my TM backup to a different drive.

http://www.mactalk.com.au/2009/05/04/ho ... ent-drive/

But I can't seem to do this on WHS because of the 'container' method, this folder/disk doesn't show up as a valid disk under Time Machine Prefs. Is there any way to move an existing TM to the WHS?

Yes, every Mac has its own MSS backup storage (as for me it is reasonable). To copy existed TM history you can try Carbon Copy Cloner to move it from your previous storage to the MSS one.

Yes, there will need to be two backup files. I have one for my Mac Pro and one for my MacBook. They are disk images, like DMG files if you like. I didn't try to migrate my existing TM files to my server as I was pretty confident that my current system state was working. And yes, all of your Time Machine files will live in the same Mac folder. They are named automatically with the serial number of your Macs (how they get that serial number is not known to me and I'd rather they asked for a file name in case I need to replace a failed computer outright.)