Archive for October 23rd, 2015

Scrubbing Old Hard Drives

The shelf that collects old hard drives filled up, so I’ve been wiping the data before recycling them. This takes a while, but we know what happens when your hardware falls into unexpected hands. The routine goes a little something like this…

Set the drive’s jumper to Master, plug the drive into the USB adapter, plug the adapter directly into a USB port on the PC (because outboard hubs tend to be flaky), make sure there’s no valuable data, unmount.

time sudo dd if=/dev/urandom of=/dev/sdc bs=4096
[sudo] password for ed: 
dd: error writing ‘/dev/sdc’: No space left on device
73259047+0 records in
73259046+0 records out
300069052416 bytes (300 GB) copied, 22276.7 s, 13.5 MB/s

real	371m19.003s
user	0m22.884s
sys		370m34.906s 

Good old dd works for me; the only trick is not obliterating the system’s main hard drive with a simple finger fumble. Numbers from /dev/urandom suffice for this purpose; that’s where most of the packaged programs get their data, too. I do hardcore style, just because.

Ordinary desktop drives, at least those from long ago, can write at a bit over 12 MB/s → 40 GB/h on the average, with the higher peak rates that generally appear in the drive descriptions remaining an occasional sight. They won’t go much faster, even when plugged directly into the system board, but it’s not as if I sit there waiting until it’s done. USB 2.0 “high speed” transfers can hit 60 MB/s, including all the overhead, so that’s not the limiting factor; I’d expect the adapter’s firmware to throttle the data long before the bus strangles.

Use gparted to write a fresh partition table with a single NTFS (because the next user will probably run Windows) partition labeled Scrubbed spanning the entire drive.

Then stack the drive neatly on the outbound heap:

Scrubbed hard drives

Scrubbed hard drives

That cardboard box isn’t quite as full of unscrubbed drives as it was a few weeks ago.

The stack in the back contains all those worthless 30 to 80 GB 5400 RPM drives from old Dells, plus a few 1.5 and 2.0 (!) GB drives from who knows where. I have a plan for those platters…