State Of The Power Systems Base 2025: The Operating Systems

February 10, 2025 Timothy Prickett Morgan

What is more important: Keeping a server platform current or keeping its operating system current?

That is a trick question, and it is tricky in two ways. First, you should keep both hardware and software current, or more precisely, keep both as current as the applications, the budget, and good sense permits. A server older than five years is going to start having component failure (usually with the disk drives and fans), and one that is 10years old has the chance of a much more catastrophic failure. However, with a machine that is five to ten years old, you can probably pick up an entire spare machine for a song and have spare parts in that eventuality if you are a DIYer.

And second, keeping the systems software stack up to date is clearly more important – right up to the moment there is a hardware crash or your hardware becomes a barrier to upgrading software because eventually new software is not available on old hardware. It is a pain in the neck to keep the software patched, considering that there are new security vulnerabilities each week, and upgrading to a new release of IBM i requires testing and qualification of applications and databases. The good news here is that IBM makes transitions to new releases and updates to existing releases through the Technology Refresh process about as easy as another other operating system maker still out there. (Between z/OS-MVS, IBM i, AIX, and Red Hat Enterprise Linux, Big Blue has the vast majority of commercial-grade operating systems installed in the enterprise.)

But, even with all of that, all server hardware and systems software providers put limits on release levels for hardware to cut down on their support matrix size and complexity as well as to encourage customers to spend a little money on new stuff.

You can’t really blame them. They have to make a living somehow, after all. Progress is our most important product, after all.

The good news, according to the 2025 IBM i Marketplace Survey from Fortra, for the IBM i base is that many of the faithful in the base know all of this, show good sense, and are moving through their progressions. (Hey, this is the day of Super Bowl LIX as we write this.) There are, we think, IBM i laggards as well as IBM i leaders, and as we have said in the past, we think that of the 120,000 unique customers worldwide that are estimated to run IBM i on Power Systems, about 30,000 of them keep relatively up to date with their hardware and systems software, and the remaining ones are hanging back on older servers running back releases – many of them that have long since gone off standard support and are even out past extended support.

As we have done each year that the IBM i Marketplace Survey comes out, we build a model out of the raw data and try to adjust for the leader/laggard split. We assume that the operating system and hardware levels of the laggards are four or five years back from the current leaders; so, in plain English American, we take the data for the leaders four or five years ago (the difference depends on when operating system releases go off extended support and how old the iron is we think they are running upon) and apply it to three-fourths of the installed base of iron that we think represents the laggards. (We get a machine count by looking at the machine count distribution of the installed base that is in the demographics of the Fortra survey, which gives us an average number of machines at each customer, which we then apply across a base of 120,000 unique customers.)

In this story, we are just going to talk about IBM i releases. We will examine Power Systems hardware levels in the follow-on story next week.

The shape of the curves for the resulting installed IBM i operating system installed base look very different if you are just talking about the leaders (which is the raw data from the survey) or if you add in the laggards who make up a large chunk of the installed base. Here is what the operating system installed base by release levels looks like from the surveys running from 2021 through 2025, inclusive:

And here is a line chart, which we think shows trends better, all the way back to 2015, the first year a report study was published for the IBM i Marketplace Survey. Take a gander:

Remember this data show in the charts is for the year the report was published, not the year the data was gathered for the report. So this is more of a statement about the state of installations in the fall of the prior year to the publication of each Fortra report. You can think of it as the state of OS levels at the beginning of the years shown, but most people think of state being measured at the end of the year. The important thing is that 2025 does not mean a projection for how this year will end up, but rather how 2024 ended.

As you can see, IBM i 7.1 was a big release for IBM, and the past surveys caught the peak just as IBM i 7.2 was ramping. And IBM i 7.2 got off to a pretty normal start, but among the IBM i leaders it flattened out between calendar 2016 and 2020 as IBM i 7.3 took off. We have seen plenty of customers skip an upgrade cycle, which the Technology Refreshes allow them to do because new function is added to the N-1 release as well as the N release at any given time. We think the flattening of IBM i 7.2 is really a reflection of the uptake of the Technology Refresh process on IBM i 7.1.

There was a similar slight flattening and decreased adoption level for IBM i 7.3 and you can see the same pattern with IBM i 7.4. Basically, 50 percent is the new peak installation level for any release, not 70 percent, but everything is easier for customers to consume and do a skip-release upgrade pattern.

Now, here is what the installed base looks like if you add the laggards in:

The peak installation level for IBM i 6.1, which debuted in March 2008, was probably in 2014 across the entire base. IBM i 7.1 came out in April 2010 and peaked among the leaders in 2016 but only peaked across the entire base in 2022 – yeah, that is six years later. IBM i 7.2 came out in May 2014, and hit a plateau that lasted from 2017 through 2020 at the leaders; across the entire base, it may be peaking now, it may push a tiny bit higher as customers on really old systems try to move to something more current (like a Power8 system). It is interesting to see how IBM i 7.2 had its own mini plateau starting in 2023, for all of the reasons the leaders loved it years earlier.

As for IBM i 7.5, across the leaders, as represented in the raw data from the Fortra survey, and massaged a bit by us to make the numbers worked, it looks like 32.1 percent of those surveyed had IBM i 7.1. If our model is right – and we think it is, obviously – only a handful of laggards are starting to move to IBM i 7.5, which is now almost three years old. And therefore IBM i 7.5 represents only 8.1 percent of the primary operating systems installed in the 120,000 installed base.

Just so you have it, here is the model data for primary operating systems at the 120,000 sites using IBM i worldwide:

We have not created a model for all of the operating systems across all of the machines, but perhaps we will do that next year.

One thought on “State Of The Power Systems Base 2025: The Operating Systems”

ema tissani says:

February 21, 2025 at 9:22 am

To visualize these things (% of versions on the entire population across time) an area chart would be nice to clearly see the evolution. With cherry on top if you mind thanks 😛

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