At work we recently retired roughly 30 servers from active duty, consolidating all into a single blade chassis. After the discussion of building a Beowulf cluster came to an end, we realized that we really had no practical use for these machines anymore, and they were actually costing us money to store them. It is time to “get rid of them”.

I don’t know if you’ve attempted to dispose of a truck full 10 year old servers before, but it can be more difficult than it sounds. Due to environmental impact issues, you can’t just throw them away.

Recycling becomes another issue: Due to the heavy metals involved you actually have to pay a fair bit to have someone take these off your hands. It was going to cost us several hundred dollars to have the servers disposed of properly.

Then there was more of a principles problem in that these servers were totally functional, and as a geeks we realized that the servers have more value than, well, negative numbers. They are worth something–or at the very least they are worth nothing!

We understood that there are many people that would gladly take these off our hands and re-use (which is better than recycle) these machines.

One of the things going for the servers is that they were each configured with a pair of 9GB 10K RPM SCSI drives attached to a Compaq SmartArray RAID controller. So each server was packed with 2 hard drives filled with confidential “company stuff” and could not be recycled without doing something to destroy the data stored on them. Simply formatting the drives or deleting the data is a simple token gesture–it can still easily be recovered by computer geeks. The question becomes: How do you irrecoverably destroy the data on 60 hard drives?

This question started a very interesting conversation on creative and/or entertaining ways to destory data stored on hard drives. Some select quotes from this conversation:

• “How much does thermite cost?”
• “If thermite is affordable, can we legally purchase and/or make it?”
• “How many platters do you suppose a .223 could go through?”
• “Would perhaps a .45 ACP be more effective? Slower but bigger?”

Reality set in after discovering that legally disposing of 60 destroyed hard drives a task equal to or harder than that of disposing of 30 complete servers. We also realized that the likelyhood of being able to sell or give these machines away would be greatly improved by including these hard drives as part of the deal.

So the problem then becomes: How do you irrecoverably destroy the data on 60 hard drives without destroying the drives themselves?

We have a pretty cool SCSI drive duplication machine that we use to replicate drives–seemed like it would have been potentially promising tool for wiping drives as well, but turns out there is no real way to make it happen.

Now if you’re just doing an just a drive or two, there is a lot of software out there that will allow you to “zero” a drive (process of repeatedly writing zeros to every possible position on a disk). The problem is that we need something that can enable us to do some wholesale dustruction of deta–none of this one-sy/two-sy business. I had a stack of roughly 100 drives in total that needed to be wiped, and don’t have time to screw around.

When searching the Internet for enterprise-grade hard drive wipers, there seemed to be one name that kept bubbling to the top: Darik. As in Darik’s Boot and Nuke (DBAN), a self-booting floppy or CD-ROM image that is perfectly suited for destroying data on magnetic media.

The cool thing about DBAN is that it is an equal-opportunity obliterator–it will pick up all drives installed in the system: SCSI, IDE, PATA, SATA, whatever. It has pretty much every SCSI driver under the sun, and immediately picked up our on-board SCSI and PCI RAID card plugged into our data-terminator server.

DBAN supports several different wipe methods, from basic (single-pass zeroing), to paranoid (35 passes of the Gutmann wipe method).

Wiping our 9GB drives using the zeroing method took about an hour, and using a reasonably secure Department of Defence Short method (3 passes) took about 3 hours. All drives are wiped in parallel, so it really paid to get many drives wiping at once–I was able to get several drive cages/backbones going, wiping about 10 drives at a time.

Over the course of a couple of days, was able to get pretty much all the drives totally wiped and ready to be re-used. Great tool!

Tags: darik's boot and nuke, data, dban, delete, destroy, erasing drives, hard drives, recovery, wipe

This entry was posted on Friday, December 21st, 2007 at 12:03 pm and is filed under Technology. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.