The explanation of the IBM Great Oaks is questionable. Most called that campus the Cottle road site. I would not be surprised if the assembly/electronics of the hard drive went to Mexico/China but the sputtering of the disks themselves was San Jose, Germany, Ireland and Singapore. I was doing sputtering for a few years out of college. We ran the last batch of the 14" disks. This was the time that the little 2 1/2" glass disks for laptops were becoming hot. The old Ulvac was being decommissioned and they did a final run of the disks as the only use at the time was for Navy submarines. After the final run, they made a plaque for head engineer for that disk program by putting a really thick layer of carbon so the disk was a beautiful dark purple. The production leads were PISSED. It took a full day to clean out the Ulvac of all the extra carbon before it could run production again. When they finally took the Ulvac out, they had stacks and stacks of the 14" disks out in the parking lot. I took a few home and gave one to a friend who added to his drum kit for a different sounding symbol.
The Ulvac was cool. It had big roughing pumps to get most the air out, then turbo pumps to get down to an almost pure vacuum then finally the cryopumps to do the rest. They were basically a large chamber with a sponge like material at the bottom that was cooled to 20 kelvin. The remaining gas molecules would eventually bounce in to the cryopumps and be less trapped but slowed down by the cold sponge...
When I was there building 50 was a ghost town. I would walk through during lunch and only occasionally would you see a room lit up and drives being assembled.