Thursday, November 18, 2010

What happens to hard drives at Free Geek?

When a piece of equipment comes in through the warehouse gate, the first priority is re-use: if there's a reasonable expectation that it can be given a second chance at usefulness, a piece of gear will get cleaned up, tested, and sent out again to a volunteer or a grant recipient, or sold through the thrift store.

There are several risky aspects in re-use – for example, those universal Windows stickers bearing serial numbers. If a machine is sent out without that sticker being removed, it could be used to install a pirated copy of Windows. The Windows license remains with the original owner and cannot be transfered. This potentially puts Free Geek Vancouver in a position of legal liability.

Another common example is hard drives. When a machine is received at Free Geek, it almost always contains a hard drive with software and user data on it – and on a typical machine, that is almost certain to contain private information, from names to resumes to credit card information to who-knows-what. One of the most common questions asked by donors is – what happens to all that data? How can Free Geek Vancouver be sure that it's treated responsibly?
40GB IDE hard drives, clean and tested and ready for Ubuntu to be installed

The process begins at evaluation (also known as “eval”). This is the station where computers are first checked out upon arrival. For example, the eval volunteer decides here whether or not the machine is suitable for re-use – if it's damaged or too slow, it's dismantled for scrap. If it's reusable, it's tested briefly in preparation for the Build Program, where it's assembled and prepared for grants, volunteer adoption, or sales in the store. One of the steps the eval volunteer will take is to remove the hard drive and set it aside for processing.
Evaluation: Drives are removed from incoming machines here

From there, the drives are taken into the mezzanine and sorted by size and by type. Recently, Free Geek Vancouver has reused drives with capacities as small as 20GB. Most machines at Free Geek Vancouver are built with 40GB or 80GB drives. A brand new home computer might have several hundred GB of storage. For comparison, a DVD stores around 8GB; a CD stores less than 1; and the first popular home computers could store only 20MB, or about 2% of 1GB.

While almost everything that Free Geek Vancouver receives is a standard IDE or SATA hard drive, suitable for use in a standard computer, there are numerous other kinds of hard drives that come in – SCSI drive arrays, which are used in servers; old MFM/RLL equipment from the dawn of home computing; laptop drives, which are processed separately at the laptop station; etc.

Once the hard drives have been sorted, the result is a shelf full of drives that are ready to be prepared for re-use, and a bin full of drives that are too old, too slow, or otherwise unsuitable. (For example, the IBM DeskStar line of drives gained a terrible reputation for failure and many of those are simply scrapped as potentially unreliable.) In either case, the drives are considered “dangerous” since they almost certianly contain personal data.
Sorted drives, ready for cleaning & testing

Reusable drives then go through two additional steps before they leave the hard drive sorting and testing area: first they are wiped clean, and then Ubuntu is intalled on them.

The wiping process uses a bank of machines at the western end of the mezzanine. Each of these can handle several hard drives simultaneously. They run a custom drive wipe script that writes over every piece of data on the hard drive numerous times. The process may take hours, depending on the drive, but serves several useful purposes. Primarily, it thoroughly removes user data from the hard drive. Simply erasing files from the disk is often not a guarantee of privacy – it's often equivalent to removing the Table of Contents from a book but leaving the pages themselves in place. Only by overwriting every part of the drive, and in fact doing it numerous times with different patterns to ensure that the data cannot be recovered by forensic means, do we know that the drive is safe.
Drive wipe stations

A secondary purpose of this process is to thoroughly test the drive. If a drive is failing, it may have defective areas, but those might not be encountered until the drive is nearly full. Drives are also capable of marking areas unusable if they have failed, which may prolong the usability of the rest of the drive, but is typically a good indicator that a drive is near the end of its useful life and might not be reliable.

After a drive has been wiped and tested, the volunteer at drive testing will put a green sticker on the label. If a drive has this label, it's considered safe for re-use. If a drive anywhere in the warehouse doesn't have a green sticker on it, it should be considered dangerous and taken up to the drive sorting station.

Beside the drive wipe machines is another shelf with several machines on it. This is where the clean drives are taken to have Ubuntu installed on them. After this is finished, they receive a yellow sticker beside the existing green one, and this means that they are ready to be used in the Build program.
Ubuntu install stations

Incidentally, the way Ubuntu Linux is designed is a great convenience here. Most operating systems – including distributions of Linux in past years – will configure themselves to the computer as part of the installation process. For example, they'll detect what kind of network hardware is installed and store that configuration for future use. Of course, since we're installing Linux on one machine to prepare it for use in another, that would be a problem.

Fortuntately, Ubuntu detects and configures the computer's hardware every time the computer starts. Therefore we're able to have a supply of drives with Ubuntu already installed upon them, ready for builders to use. In the past, it was necessary to install the drives into the machines empty and then install Ubuntu from the network (or worse, from a CD) , and this delayed building significantly. (There are occasional limitations in Ubuntu's ability to detect and install hardware support automatically, and these are often related to intellectual property and licensing. Certain video cards and wireless network cards, for example, require a little bit of manual intervention before they'll function.)
Build bench, with cleaned, tested & preloaded hard drives visible beneath, sorted by size.

And what happens to hard drives that couldn't be successfully wiped clean, or that weren't suitable for reuse? These are disassembled and crushed. The controller boards are recycled through a circuit board recyclers; sometimes it's possible to recycle aluminum parts separately.
Drive controllers, removed from drives and ready for recycling

The spinning platters themselves that store the data are physically broken so that they can no longer spin.
Scrap hard drive, controller removed and platter crushed (note the hole in the casing)

As with any of the stations where volunteers work with scrap, this is a good opportunity to look at how a hard drive works!
Inside of an old hard drive, platters and magnets removed -- basically a record player.
The stack of platters that hold the data have been removed, leaving only the central spindle. You can see that a hard drive is basically a record player. The read head, which works just like the needle of a record player, has also been removed.

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