if you are using win7 you can do this natively thru the the disk management inteface (diskmgmt.msc) and span a dynimc volume across (up to) 32 disks
I should have been more specific in my initial post. I want to add a blank 4tb disk to a dynamic volume which already has a ton of data on it, and end up with a new, spanned volume that's twice the capacity yet still has all my data intact
like it did before adding the new 4tb disk. Are there any caveats I need to know in doing this the way you suggested?
Also, will I have to do anything to the 4tb drive I'll be adding to the existing 4tb dynamic volume beforehand? Does it need to be formatted at the very least? Anything else?
And then once I have the new dynamic volume, which will total 8tb, what software can I use to manage it? AOMEI Dynamic Disk Manager says that it only works on dynamic volumes up to 5tb in size.