I worked for a large Aerospace company in Britain for many years, they decided to do a data centre consolidation to reduce costs.
On the Friday night they took the systems offline, backed them up and on Saturday shipped all of the tapes by road to the new site some 150 miles away. By 7pm on the Saturday they had failed on a critical milestone so the person in charge of overseeing the migration called for it to be reversed.
The driver of the truck after dumping his load of tapes at the new site had driven the 150 miles home and was busying himself in the pub. The area where the new site was was pretty sparse in trucking companies and as it was pre internet no online resource to find any. They ended up hiring a fleet of taxis to bring the thousands of tapes back in their boots, back seats, passenger footwells and probably ashtrays as well.
By Sunday evening the systems had been restored. As the doors to the server room had been wide open since Friday things were getting a little warm in there. They called maintenance to have a look at the chillers to make sure everything was OK. The maintenance guy walked over to the main chiller \ power distribution wall and pulled the server room master power switch and not just the chiller power.
All of the old IBM DASD disk packs powered down, she swore and pushed the power back on spinning the disks back up part way through their spin down cycle.
12 hours later, 5 minutes before the Monday morning shift were due to come in, we managed to get the factory systems online. I had been on overtime since 5pm Friday all the way through.
Next week we tried again, all sorted by 7pm Sat so not so good an earner