There was recently an article by facebook about how they're building/deploying a cold-storage datastore[1] which amongst other things, uses custom HDD firmware:
"The biggest change was allowing only one drive per tray to be powered on at a time. In fact, to ensure that a software bug doesn’t power all drives on by mistake and blow fuses in a data center, we updated the firmware in the drive controller to enforce this constraint."
There's been plenty of speculation that this is similar to how Amazon Glacier works - lots of mostly unpowered disks, with custom firmware.
I presume when they're buying in suitable quantity, they can get direct manufacturer support with these sorts of modifications.
I saw that, I just didn't remember all the details. Well anyway, that's a good counter-example. What if a smaller company wants to do the same?
There might be an argument that it should require knowing the serial number or something that's only printed on the disk, so it couldn't be done by malware.
How about having the digital signature check controlled by a physical switch on the side of the drive that defaults to "enable"? Sort of like the write protect tabs of yore.
Anyway, I wonder about the feasibility of writing your own firmware like this. The stuff is so complicated that it seems impractical to do it usefully on a production-ready level without the cooperation of the manufacturer. In an ideal world the firmware would be open source and we could tweak it as we wished, but absent that, it seems like more of an abstract concern.
"The biggest change was allowing only one drive per tray to be powered on at a time. In fact, to ensure that a software bug doesn’t power all drives on by mistake and blow fuses in a data center, we updated the firmware in the drive controller to enforce this constraint."
There's been plenty of speculation that this is similar to how Amazon Glacier works - lots of mostly unpowered disks, with custom firmware.
I presume when they're buying in suitable quantity, they can get direct manufacturer support with these sorts of modifications.
[1] https://code.facebook.com/posts/1433093613662262/-under-the-...