Bare metal back up of an external drive

[heymrdj]

Due to old limping hardware, I'm leaving my WHS server shut down until I can afford to build a new FREENAS 8 rig. But for now I still need daily backups. So here's the thing. I have a 1TB external hard drive that i used with WHS for backups of WHS. Since that server isn't running for now, can I take that drive and do a block level back up of it (through USB without taking the drive out), use the drive for doing backups for now, and then restore that block level back up back onto the external drive when i'm ready to boot back up WHS in 2 months or so when I can afford to make a replacement? Will WHS still treat the external drive the same when I plug it back into the same port before that WHS server boots back up after doing a block level restore?

I could afford to buy another drive, but I'd really prefer not to. It'd be awesome if I could just take this 1TB drive, plug it into my router, and make it shared storage for my two systems to back up to for now.

Thanks!