Why can't you rename the host if its function changes? Like if "the 1U box with asset tag XY1Z234" goes from being a web server to a DB server, why not reinstal

Why can't you rename the host if its function changes? Like if "the 1U box with asset tag XY1Z234" goes from being a web server to a DB server, why not reinstall it and call it db03? I think the approach of naming the host "freddy" works for small installations (and all installations in 1990 were small), where reinstalling a single server is a manual process and impacts your capacity, and where humans remember "Oh, freddy is the one with a very large hard drive." If you've got any sort of automation, let alone virtualization, you should be keeping facts about hardware somewhere other than people's heads and so you can index them by the actual identity of the hardware - the fact that web04 had a large disk last year is remembered by a field on your inventory entry for XY1Z234, not by any human. And reinstalling web04 as db02 is just a matter of running a script from the comfort of your work-from-home laptop - certainly no need to visit the datacenter. I think this lines up with your point about pets being higher levels of abstraction - I wouldn't point any DNS client at dns01, since that's a specific server, I'd point it at a virtual IP that can be bound (possibly multicast) by any dnsNN server that happens to be up. That virtual IP is the pet and the API surface, and it belongs to no actual server.