Forum Discussion
26063 deduplication data corruption is still there.
From Server 2022 up to this newest 26063 build, they all have the same problem, as described here: https://techcommunity.microsoft.com/t5/windows-server-insiders/server-vnext-26040-and-server-2022-de...
MSBernstein
Microsoft
MicrosoftI checked on the bug report. As far as I can tell, the engineering team is still working to reproduce the issue.
I can still perfectly reproduce this with build 26212, with 100% reliability, I suppose I have to recommend not using deduplication in Hyper-V on the local volume hosting the virtual machines with both Server 2022 and Server 2025.
https://techcommunity.microsoft.com/t5/windows-server-insiders/server-2025-hyper-v-deduplication-corruption-is-still-there/m-p/4136286
https://techcommunity.microsoft.com/t5/windows-server-insiders/server-2025-hyper-v-deduplication-corruption-is-still-there/m-p/4136286
- MSBernsteinHi, Joachim. MSSWRahman had asked you for a full dump and logs - were you able to hand those off? I understand that you can perfectly reproduce the issue, but we have not been able to reproduce this in-house at all.
The full dump and the logs are requested for a different machine, an i7-4960x running Server 2022, which did no crash again yet to have such a dump - I activated the "full dump please" option. That single crash may be completely independent from that deduplication issue, which I reproduce in machines I have more confidence in (both have ECC RAM, for example). The i7-4960x machine may show its age since it is eleven years old now, so I have to rule it out as reliable test machine for the deduplication issue.
