{"id":1337,"date":"2025-11-05T10:42:31","date_gmt":"2025-11-05T09:42:31","guid":{"rendered":"https:\/\/blog.chrisse.se\/?p=1337"},"modified":"2025-11-07T23:01:04","modified_gmt":"2025-11-07T22:01:04","slug":"8k-page-size-dits-on-windows-server-2025-and-ntdsutil-might-destroy-your-dit-forever","status":"publish","type":"post","link":"https:\/\/blog.chrisse.se\/?p=1337","title":{"rendered":"8k page size DITs on Windows Server 2025 and NTDSUTIL might make your DC unbootable"},"content":{"rendered":"\n

All DIT’s on Windows Server 2025 isn’t 32k page size (Yes I know – I did say that in my last blog post), there is two exceptions, 1: the IPU case aka In-place-upgrade of a pre-Windows Server 2025 DC, in that case the DB will remain as-is in terms of page size.<\/p>\n\n\n\n

You can verify the actual page size using a new attribute msDS-JetDBPageSize<\/a> to determine the page size of a Windows Server 2025 DSA.
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This clearly show us that the page size of the one and only DSA running Windows Server 2025 is 8k – this is because the DIT comes from a an IPU’ed aka in-place-upgraded Windows Server 2022 DC.<\/p>\n\n\n\n

Let’s have a look with esentutil \/m C:\\Windows\\NTDS\\NTDS.dit<\/p>\n\n\n\n

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For sure the DIT is 8k page size, we can also validate by it’s DB Signature that it was created back in 2017, we can compare with the Distribution DIT that is 32k page size and created in 2023 – more on the Distribution DIT can be found here<\/a>.<\/p>\n\n\n\n

So how do we get to 32k page size on this DC? The answer is you can’t unless you demote and re-promote it. You can get to Windows Server 2025 DFL and FFL – but you can’t enable the “Database 32k pages feature”<\/p>\n\n\n\n

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There is is a 2:nd way to get up additional DCs running Windows Server 2025 with 8k page size DIT’s.<\/p>\n\n\n\n

If you produce IFM media of a Windows Server 2025 DC with 8k page size – the Windows Server 2025 DCs you promote using that IFM media also going to have 8k page size of their DITs.<\/p>\n\n\n\n

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IPU-DC-02 is promoted using a IFM produced off IPU-DC-01 that once was IPU:ed (In-place-upgraded) from Windows Server 2022.<\/p>\n\n\n\n

Extensible Storage Engine \u2013 ESENT and the Engine Format Version<\/strong><\/p>\n\n\n\n

Some where after Windows 19H1 version 1903 – released in May 2019 and within Windows 20H1 version 2004 – ESENT seem to have got support for something called “EngineFormatVersion” that enables specific features depending on the ESE Engine version – by default if a ESE DB is attached on a more recent engine than the ESE DB was initially created on, it and it’s logs are upgraded to the current ESE Engine version, that might break backwards compatibility to be able to attach the ESE DB by a older version of the ESE Engine (older version of the operating system with an ESE Engine only supporting certain EngineFormatVersions) – this is by default aka:<\/p>\n\n\n\n

ESENT.h<\/span>