So essentially they sell new hardware and "support" to customers who have been in need to process tabular, multi-GB databases since when a PC was 128MB memory and have been doing electronic record-keeping since the 1970s. They also allow their ~hostages~, ehm, customers who trust them with their data to run processing near the data at a cost/in a cloud style billing model. That is so expensive though that every large IBM-shop has built an elaborate layer of JVMs, Unix and mirror-databases around their IBM appliances. Lately they bought Redhat and hashicorp and confluent thus taking a cut from the "support" of the abominiations of IT systems they helped birth for some more time to come (also remember the alternative JVM OpenJ9, do you all?).

I think the later a company started using centralized electronic record keeping, the higher the likelyhood they are not paying IBM anymore: commercial banks, governments and insurance started digitizing in the 60s (with custom software) and if the companies are old (or in US-friendly petrostates) they are all IBM customers. Corps using ERP or PLM offerings (so manufacturing and retail chains which are younger than banks) used to start digitizing a little later (Walmart only was founded in the 60s and electronic CAD started in the 80s) and while they likely used IBM in the past (SAP was big on DB2) they might not use it anymore (also it helps they usually bought the ERP or PLM from someone else). New Companies whose sole business was to run a digital-platform started on Unix (see Amazon who successfully fought to ditch Oracle even) or just built their whole platform (Google). If those companies predate Unix they usually fought hard to get rid of IBM (Microsoft, Amadeus)

Consulting/outsourcing services have been spun out to Kyndryl, so nowadays IBM only sells hardware, support for their products and ostensibly has some people left to develop their products... The days when that was a big thing and IBM produced all the stuff they sell support for now, have been long gone. A fun link to see how their "product development" operates nowadays is this discussion to bring gitlab-runners to z/OS: https://gitlab.com/gitlab-org/gitlab-runner/-/work_items/275... - tl;dr "hey you opensource company, we are IBM and managed to pay someone to port a go compiler to z/OS. Now we have a customer who wants to use gitlab with z/OS. Would you like to make your software part of our product offering?". A fun fact is that - even within IBM - access to the real mainframe seems to be very limited which shows a bit in the discussion linked above and also with an ex-Kyndryl-person saying: "oh, I once had a contract where we replaced the mainframe and we ran that on Linux-boxes inside IBM, because it was just cheaper that way. Just the big reporting was a bit slow, but the reliability was just fine"

very fun!

here that person is a manager which got demoted from ~500 reports to ~40 and then convinced his new boss that it's good to reuse his team for his personal AI strategy which will make him great again.

We also sublease our mainframes to at least 3 other ventures; one of which is very outspoken they have left the mainframe behind. I guess that's true if you view outsourcing as (literally) leaving it behind with the competitor of your new system... It seems to be the same for most banks, none of which are having mainframes anymore publicly, but for weird reasons they still hire people for it offshore.

Given that our (and IBM's!) services are not cheap I think either a) our customers are horribly dysfunctional in anything but earning money slow and steady (...) and b) they actually might depend on those mainframe jobs. So if you are IBM or a startup adding AI to IBM I guess the numbers might add up to the claims.

Sadly devs are incentivized by that and going towards the cloud might be a fun story. Given the environment I hope they scrap the effort sooner rather than later, buy some Oxide systems for the people who need to iterate faster than the usual process of getting a VM and replace/reuse the 10% of the company occupied with the cloud (mind you: no real workload runs there yet...) to actually improve local processes...

So while you can have single-system-images on a relatively large multinode setup I doubt many people are doing that (at the place I know, no LPARs have TB of memory...). Also in the given price-range you easily can get SSI-images for Linux too: https://www.servethehome.com/inventec-96-dimm-cxl-expansion-...

If you don't need the single-system-images, VMWARE and Xen advertise literally the same features on a blade chassis minus redundant hardware per blade, which is not really necessary when you just migrate the whole VM...

Also if you define the whole chassis as having 120% capacity, running it at 100% capacity becomes trivial too. And this is exactly what IBM is doing keeping around spare CPUs and memory in all setups spec'ed correctly: https://en.wikipedia.org/wiki/Redundant_array_of_independent...

You are right though that the hardware was and is pretty cool and that kind of building for reliability has largely died out. Also up until ARM/Epyc arrived maximum capacity was over-average, but that is gone too. Together with the market-segment likely not buying for performance I doubt many people today are running workloads which "require" a mainframe...

[0] https://www.redbooks.ibm.com/redbooks/pdfs/sg248951.pdf

Your point that TCO is lower than a well executed alternative seems very dubious to me though. Maybe lower than cloud and also certainly lower than whatever crap F100-consultants sold you, but running database unloads with basic ETL for a few dozen terrabytes per month creating a MSU-bill in the millions is just ridiculous. The thing which probably lowers the TCO is that EVERY mainframe-dev/ops-person in existence is essentially a fin-ops-expert formed by decades of cloud-style billing. Also experience on a platform where your transaction processing historically has KB-range size limits, data-set-qualifiers are max. 44 chars, files (which you allocate by cylinders) don't expand by default and whatever else you miss from your 80ties computing experience naturally leads to people creating relatively efficient software.

In general even large customers seem to agree with me on that (see Amadeus throwing out TPF years ago) with even banks mostly outrunning the milking machine called IBM. What is and will be left is governments. Captured by inertia and corruption (at the top) and being kept alive by underpaid lifelong experts (at the bottom) who have never seen anything else.

> during the AWS outage this week.

Also the reliability promises around mainframes are "interesting" from what I've seen so far. The (IBM) mainframe today is a distributed system (many LPARs/VMs and software making use of it) which people are encouraged to run on maximum load. Now when one LPAR goes down (and might pull down your distributed storage subystem) and you don't act fast to drop the load you end up in a situation not at all unlike what AWS experienced this week: critical systems are limping on, while the remaining workload has random latency spikes which your customers (mostly Unix systems...) are definitely going to notice...

The non-IBM-way of running VMs on a Linux box and calling it a mainframe just seems like a scam if sold for anything but decommissioning. So I guess those vendors are left with governments at this point.

Now, if you can live with the weird environment and your people know how to programm what is essentially a distributed system described in terms noone else uses: I guess it's still ok, given the competition is all executing IBMs playbook too.