On Mon, Apr 23, 2018 at 2:41 PM, Noel Chiappa <jnc@mercury.lcs.mit.edu> wrote:

Speaking of fixed-head disks, one of the Bell systems used (IIRC) an RS04
fixed-head disk for the root. DEC apparently only used that disk for swapping
in their OS's... So the DEC diagnsotics felt free to scribble on the disk.
So, Field Circus comes in to work on the machine... Ooops!

teklabs 11/70 the RS04 was /tmp not quite an dangerous as root, but since the fs got wiped out the system would not boot - as it would fail trying to mount /tmp.

IIRC the it was the field exerciser that did that by default. I seem to remember that you could configure it to use something else like the field service pack itself or may be not disk at all, but if I remember right if the exerciser found an RS04 it thought it was available by default. So, I had a big sticker on the FS pack that said see me before you loaded it after the first time the service guys took out /tmp.