Ah, that takes me back..
I had a room full of 80Mb five-platter CDC drives attached to a variety of PDP-11's, and another room with a somewhat more up to date VAX 11-750 and a bunch of MicroVAXs, with fixed disks. I spent most of my day feeding various paper stocks into various large printers, and responding to user requests to load pack X into drive Y, eventually awaiting the signal at 5pm that the day upstairs was done, and I could start the daily disk pack suffle that was the backup process.
Users felt they were in control, but I'd get the occasional stupid request. There was one system with two drives, and one head developer who used it remotely at 300 baud. Load pack Y4 into drive 2. Yeah sure, but no drive 2, only drives 0 & 1. So I dismounted and spun down drive 1, loaded Y4 in place of Y1 in it, spun it up, mounted it, andtold this prima-donna that it's available. Same request. So I reply 'in 1, no 2'. As he's using his phone line to remotely work, phone calls and the simple text messaging set up can't work at the same time. The phone rings, demanding to know why I have used drive 1 instead of the non-existent drive 2. Demanding also that I reload Y1 back into drive 1 immediately. So I do that. Next phone call, wheres Y4? I still need it. Look mate, make your mind up!. So he demands I put it in drive 0. Did Y4 have an operating system on it? Suffice it to say I didn't get any more requests of that system for the rest of the day while the system wondered where it's system disk went,and the user concerned learnt to count from 0, not 1.
It didn't end there, the next day, we then got an order to move a drive from the production system onto 'his' development system. Not a simple job because the system concerned only had controllers and/or cabling for two drives, and power supply was another issue. We sent the job back with those details, and waited for the go-ahead from the boss, which never came. Apparently the guy thrrew a hissy fit and said something unfortunate to the boss, who back in those days knew all the technical ins and outs of the system. Various things were said, and no further requests came from that user, ever again.
Never had this problem with the VAXen in the other room. The users, of which there were far more, generally only wanted the occasional tape mounted, and the users knew how to request volumes properly, and even made sure no two tapes had the same label. (Such levels of clue are unusual!) Requests came through OPCOM, and the system would assign devices to users and all I'd have to do is physically load the volume and bring the tape device concerned online, and the system would take care of the rest, with only the occasional need to resort to REPLY/PENDING=requestno "Where the heck is that tape?". There was clever stuff built in too, such as when you'd failed to find the tape the user wanted in MSA0 because it was already loaded into MSB0, you could REPLY/TO=requestno "SUBSITITUTE MSB0" and the user's request would complete, and if they'd followed the rules and specified a logical name when mount the volume, unless they were paying close attention, they'd be none the wiser. Somehow a different class of user. Different class of OS too, as we'd occasionally get requests to mount a TK50 cartridge in a large magtape drive, and we'd just use the same method to switch the system's attention to MUA0: instead of MSxx:, usually follwed by by a REPLY/USER=DIMWIT "Remember, your new system's data is on TK50's, please use MUA0 next time", and sometimes they did. Just shows that regardless of how clued your users seem to be, give them a choice, and they will make the wrong one.