I often have to transfer large files >50GBs sometimes >100GBs between drives both internal and external during backups of our networks email servers. What is the best method of
Well i use http://itrnsfr.com to transfer my big files online. I wish they extend the quote over 2 GB they currently offer to free users
For free, I use SyncToy (from Microsoft). That way if something fails it doesn't abort the whole transfer.
The next best for non-repetitive tasks IMHO is XCopy.
I get asked this question every now and again and I always say the same thing. Microsoft Background Intelligent Transfer Service (BITS). This is the same technology used to deliver large service packs and such to workstations. Some of the features:
For those not wanting to deal with the command line syntax you can explore wrapper applications, such as SharpBITS.NET, that provide a GUI interface.
I use CopyHandler and find it does the job well.
Check out robocopy. From Wikipedia:
robocopy, or "Robust File Copy", is a command-line directory replication command. It was available as part of the Windows Resource Kit, and introduced as a standard feature of Windows Vista and Windows Server 2008.
I have used Teracopy with good success.