I only reply to ACs after we both identify ourselves once. I despise AC snipers... they come along and post only once to say "You're wrong." and then disappear. But anyway..
Now, you're not, realistically, going to get 10,000 hosts in a rack, with reasonable performance on each of those hosts.
Depends on the workload. A great many of them will be very lightly loaded. And a few will run IRC fserve bots. YMWV.
Yes, Test Plan Charlie got 41,400 in a box, and a later test, 97,900 (both of those, btw, were on the 31-bit System/390 architecture;
I know. Unless you are David Boyes, STFU.
those were, in fact, stress tests, not practical environments. The work I've done suggests that you could fit about 5000 lightly-loaded machines onto a full-up zSeries with acceptable performance
z900? z800? IFL? VM Guest?
Also: 5 to 10 minutes? You're doing something wrong.
No, I was being modest. I have scripts for cloning and booting new servers in 90 seconds. I didn't want to post best-case numbers. Granted my 5-times multiplier of the worst case may have been a little too conservative, but I actually stake my name on my posts.
If you have either DASD that [blah blah blah] then the time gets down to about 45 seconds. If you're willing to live with statically assigned [blah blah blah] to get your [blah blah blah]. That's the time from when you click your "build me a server" button on the web form to the time you can ssh into your new server.
You can tell all that to someone who needs one of your lessons.
Instead of stopping by to say, "Yeah, I guess you could run a small to medium-sized ISP out of an apartment using hardware that brings five 9's to Linux", you instead chose to pick apart my idea, saying that I was wrong in that I can only replace 60 racks with 1 instead of 120. Instead of saying, "hey, I work for IBM, too, let's hook up on w3", you instead choose to say, "you're wrong." Here's hoping we never work together.