Server vNext 25987, 26010 (and Server 2022) deduplication corruption in nested-V setups
The deduplication corruption in the case of nested virtualization in Server 2022 and Server 25987 is still there. The package to reproduce for Server 25987: https://joumxyzptlk.de/tmp/microsoft/s-vnext-25987-dedup-problem-2023-11-03-exported-from-S2019.7z Server 2022 variant: https://joumxyzptlk.de/tmp/microsoft/S2022-nested-2023-09-30-exported-from-S2019-host.7z Host OS can be Server 2019, Windows 11 21H2 or Server 2022. CPU must be reasonable fast (i.e. from somewhere 'round 2018), support nested-v together with the Host OS (AMD and Intel CPU are fine). Host should have at least 24 GB RAM. The the "ready to reproduce package" must be unpacked to 😧 or higher drive letter which should be at least SATA SSD storage. Else the problem may not show up as predictable as it does here. These packages were exported from a Server 2019 host, HP DL 380 dual Xeon 6228R with 1 TB ECC RAM, so it is easier to reproduce since Exports from Windows 11 don't import so well on other hosts. Originally the bug showed up on a Ryzen 5950x with 64 GB ECC RAM. Reproduced with less than 50% chance on an i7-4960x 32 GB RAM with HDD storage, more than 50% on SSD storage. Server 2019 variant: Does exist, but there is no data corruption. How to use: Once unpacked to Non-System-Drive SSD storage import the the VM and follow the Textfile on the desktop. In short: Activate Hyper-V in that VM, default settings. Configure deduplication with default settings any profile in that VM for D:, start a dedup run. Check dedup rate. Should be above 50%, usually it is around 55%. Import those two VMs on drive 😧 of that VM: Start them both in parallel, and execute the Offline-Windows-Updates stored on the desktop. You won't make it past the first one.