How to force ssh to use a specific private key?
``` ssh -F /dev/null -o IdentitiesOnly=yes -i
``` ssh -F /dev/null -o IdentitiesOnly=yes -i
“It destructively writes blocks of random data to an entire disk device (or, optionally, just a partition; but you'll probably want the whole drive), then verifies that the data matches what's been written.
“If any data could not be read exactly as written, it informs you in big letters. That means your disk is bad & you should make use of your vendor's RMA policy. Doesn't it feel great to not run into problems?”