MichaelMeissner:
In terms of the old washing machine style disks, when I had been at Data General for a year or two, we were beginning the software qualification of the MV/8000 or Eagle that was the machine at the core of Tracy Kidder's Soul of a New Machine. My part begins after the end of the book, when the machine had been delivered to the software groups. In my case, I was one of the programmers on the DG/L compiler, which was Data General's version of Algol 60, and I had one of the large removable CDC disk platters to mount on my test system. Just as in all hardware bringups, time on the initial machines was very limited, and I pulled some 3am shifts to get the s/w validated.Now, at that time and place, most of the disk platers were a whopping 180 megabytes of space, but I had one of the relatively rare 277 megabytes of disk space. At the time, we only had 6-8 of these drives in the Westborough facility. At one point, I had a head crash on the disks (where the disk head was out of alignment and crashed into the disk platter). Not knowing what a head crash was, I swapped disks and tried to boot with the standard disk so I could run FIXUP on the disk, thinking it was just a normal OS crash. Now we had 2 drives with broken heads.
Field Circus takes down the first machine, and I or somebody else takes the disk to another drive to run FIXUP, and now we have 3 drives down. Somebody else does the swap the drives trick, and now we have 4 drives down. Somehow, it doesn't end there, and somebody else swaps drives on a different machine, and now 5 drive are now broken. They took the entire Field Circus case over to watch the rebuild, since it didn't happen so often.
I was a field service engineer for Varian Data Machines (later bought up by Sperry Univac) in the 70s and knew well of that type of failure, that if a disk drive had a head crash that one should never attempt to mount the removable disk pack involved in the crash into another different functional disk drive, as it would only then cause a new head crash on that drive. Usually took a customer at least one first hand experience before that lesson sunk in. Their lose wasn't in the drive (other then downtime) as they usually had a service contract with us that covered that, but the lose of the disk pack which was like $1,200 for the ten platter disks was not covered by us. As I recall we sold our two drawer disk drive (about the size of a pizza oven) for around $50,000 at the time. Boy has the cost of computing been reduced. Heck we charged around $1,200 a month just for the field service contract on our average minicomputer system.
Lefty