[tlb]

"Before a decommissioned encrypted storage device can physically leave our custody, it is cleaned using a multi-step process that includes two independent verifications. Devices that do not pass this wiping procedure are physically destroyed (e.g. shredded) on-premise"

Why not just shred all decommissioned disks? Someone must be buying them for enough money that Google created a multi-step process for cleaning and verifying them. Presumably Google keeps disks in commission until they're no longer economic in their own operation.

So, does anyone know about the operation that makes profitable use of disks that are no longer economic for Google?

[phire]

Probably because of the verification.

You can't really verify a shredding, the pile of shredded remains no-longer has a serial number. I assume the cleaning process cryptographically verifies the identify of the disk both before and after the wipe, making it impossible to sneak a drive out.

For those drives which fail the cleaning process, they probably have a complex process with multiple witnesses to ensure it actually gets shredded.

[willk]

My guess to the decommissioned disks is that HDD manufactures will sometimes give a hefty discount on disks if they can have them back at the end to run diagnostics on them. My company has a no disks leave the company policy and there has been talk about modifying this for the discount on disks.

[wang_li]

I'd imagine it's easier to recycle an intact HDD than a jumbled mix of silicon, ceramic, steel, aluminum and what not.

[hodgesrm]

Just speculation but they could be used elsewhere in Google for test/dev or pre-prod environments.