If I connect an external HDD to my mobo by eSata port, will I be able to access that HDD from my eth0 WITHOUT having it a part of my array.  In order words, would it be treated as any other external HDD?  I don't know if I want to spend the bucks for it not to work.  Would I be able to copy files from it to my array with a program such as Teracopy?

 

Would I be able to use an eSata shoe to say preclear a 4T drive to have ready as a "ready drive" in case of drive failure?

I do this all the time for preclears and creating backups. Search for SNAP plugin

Instead of using Teracopy though it would be much faster to use mc (Midnight Commander) from console or telnet if you are copying to a drive attached to the server. If you use your Windows machine to copy between two drives on the server the data will have to travel across the network to your windows machine and then back across the network to the server. Midnight Commander is built in to unRAID and is easy to use. Just type mc at the prompt.