The ITAM Review

News, reviews and resources for worldwide ITAM, SAM and Licensing professionals.

IBM ILMT & Windows Server 2008: Friends no more

This article was written by Rich Gibbons, ITAM Review and Eric Chiu, Managing Director, FisherITS.


IBM sub-capacity licensing allows you to license IBM software for less than the full physical capacity of your servers i.e. only the virtual cores running IBM applications instead of all physical cores in hosts or clusters. IBM don’t make it particularly easy to remain compliant in regard to sub-capacity and, for those organisations who get it wrong, licence penalty fees can typically be 6 to 10 times higher than the usual licence fee.


Most are aware of the requirement for running ILMT in order to be eligible for sub-capacity licensing but there are other conditions too – one of which is that your IBM software must be running on “eligible virtualization technologies”.

IBM publishes a list of these eligible virtualization technologies and eligible operating systems – which you can find here. However, as with so many things from software vendors, it is down to customers to review this document whenever it is updated to identify changes and ensure their estate is up to date.

Windows Server 2008

Following the scheduled end of support for Microsoft’s Windows Server 2008/R2, IBM has announced it will remove Windows Server 2008 from its list of “eligible virtualisation technologies” … but the actual date this will happen is up for debate.

The aforementioned eligibility document states you will have “180 days” to migrate to approved technology and implies this starts from the end of Microsoft support on January 14, 2020 – which takes us to July 12, 2020. However, this IBM support page – – states they plan to remove Windows Server 2008 from the eligible technologies list by the end of Q3 2020, which is September 30, 2020. Considering the potentially huge costs involved if an organisation is deemed to be ineligible for sub-capacity licensing, I would think that absolute clarity around when this change actually happens would be the least IBM could do!

You’ve got between 4 to 6.5 months (at the time of writing) to get things sorted.

Ah – but what about…

Microsoft Extended Security Updates (ESUs)? Yep, I wondered about that too – it would make sense, right? If IBM are removing the sub-capacity eligibility because Microsoft no longer support the OS, then if there’s a way of extending the Microsoft security updates that would also extend the IBM support – right? Wrong!

It appears to be the case that even if you purchase Microsoft ESUs and gain another 3 years of security updates for your Windows Server 2008/R2 systems, you will still be out of compliance with IBM.

Next steps

If you are using IBM PVU/RVU sub-capacity licensing – you need to identify any Windows 2008/R2 servers within that environment. In fact, while you’re there you should look for any other old Windows servers too – just in case!

If you find any, then you need a plan to get them out of your IBM environment. The fact that these servers are still present, beyond their 10-year support lifetime, suggests that either:

  • There is a real need for these operating systems – perhaps a critical 3rd party app


  • There is no easy, smooth, regular server OS upgrade process within your organisation.

Whatever the case, 6.5 months at a maximum (and ticking) is not a lot of time to perform the analysis, talk to the required people, decide, and then make the required changes to ensure your IBM environment remains sub-capacity eligible. However, if you don’t manage to get this done in time, your next IBM audit could be expensive.

Update: May 2020

IBM have announced they are delaying the removal of Windows Server 2008/R2 as a sub-capacity eligible technology – the new date is now the end of Q1 2021.

You can learn more about IBM licensing with LISA, our online, on-demand training portal.

Further Reading

IBM Virtualisation Eligible Tech list
IBM Support page
Microsoft ESUs
LISA training
IBM IASP audit program
IBM update announcement

About Rich Gibbons

Rich has been in the world of IT and software licensing since 2003, having been a software sales manager for a VAR, a Microsoft licensing endorsed trainer, and now an ITAM analyst looking at software licensing and cloud.

A Northerner renowned for his shirts, Rich is a big Hip-Hop head, and loves travel, football in general (specifically MUFC), baseball, Marvel, and reading as many books as possible. Finding ways to combine all of these with ITAM & software licensing is always fun!

Connect with Rich on Twitter or LinkedIn.


  1. Garth says:

    ESU = Extended Security Updates. Not Extended Support Updates. ESU only provides Critical and Important security updates for up to 3 years after the end of Extended Support.

    ESU does not include any Microsoft support. Support after the end of Extended Support would be negotiated would require a Premier or Unified support agreement that specifically includes the products that are no longer covered by standard and extended support.

    It I’d important to differentiate between Support and ESU as they are quite different.

  2. Rich Gibbons says:

    Hi Garth,

    Good point – I’ve updated to make it clear the ESUs are security update focused.


Leave a Comment