However, the biggest thing to remember is that you can and should run Linux on these things as well. Linux on z, or zLinux as it for some reason is called, is just Linux on the redundant and fault tolerant mainframe hardware. Anyone with Linux experience could manage it really, and you would get a pretty damn good platform to build a high availability service on.
https://developer.ibm.com/mainframe/2018/01/19/reasons-host-...
Still holding a Hp dos pocket whilst working on all these.
ThOse were the days. Different very much from using a mac to run leela zero using egpu :-)
The TL;DR is that some might want to rather run 1 or 2 systems (mainframe) instead of 100 physical machines (conventional distributed cattle system).
Now, IBM does make it quite expensive but the mainframe has some pretty cool features like pay-for-what-you-use (which you of course get with the cloud, but not so much if you also want your data in-house).
Anyway, it is a fun beer topic if nothing else :-)
Context: I work for a large organization that used to run several physical Z13 mainframes, all of them containing several sysplexes. If we had issues, an IBM consultant would fly in within the day. We were definitely not IBM’s biggest customer but we were not insignificant for them either.
We had a lot of mainframe support staff (so not people programming for mainframe but people maintaining storage, DB2, z/OS upgrades etc.) and I think even for them, the IBM bill was more or less: we see a large number, no idea why it’s this amount, but we cannot prove it is not right, so I guess we’ll just pay it.
Mainframe billing is really complicated.
