I am using hyper-v and I am looking for ways to backup the virtual machine. I know I could just shutdown the virtual server and copy the files, but obviously that is not a good option with a server.
I am wanting to copy/backup to an esata drive (that way i can swap 1tb drives when they get to 75% capacity)
Yes, I am currently using CloudBacko Hyper-V for backup of my virtual machine, physical servers, or databases, there are a number of choices for hyper-v backup - altaro, Veeam, Microsoft, etc. But I use CloudBacko Hyper-V VM because it has a unique feature it is 100GB of VM can be backed securely up within a few minutes!
In our company we use several backup software tools, including BackupExec, BackupChain, and Acronis. Some tools are better with external hard drive rotation than others; I guess you could try them all and see which one suits your needs better