troubleshooting Question

Hyper-V VMs see maximum of 8 processors but no more

Avatar of Dimarc67
Dimarc67Flag for United States of America asked on
Windows Server 2019Windows OSWindows Server 2008Hyper-V
8 Comments1 Solution132 ViewsLast Modified:
Environment:
Four-node Windows Server 2019 Hyper-V cluster, balancing 80 VMs.  Cluster was created over 6 months ago, is stable, and migrates/balances VMs successfully.

Issue:
Three identical VMs running Windows Server 2008 R2 were changed to increase processors and memory from 8/16GB to 16/32GB on 9 January.  It was discovered today that the guest OS only sees 8 processors instead of the configured 16.  No other changes were made, and we have other similar VMs that run 16/32GB without issues.

Using PowerShell we're unable to find any differences in the VM configuration between VMs seeing all 16 processors vs. the three VMs that don't.  Reducing/increasing processors and memory on the three VMs makes no difference.  Allocated memory is recognized as set, but no more than 8 processors are recognized by the guest OS.

We've confirmed we can create a new VM and attache the existing virtual disk to side-step the issue, but this is cumbersome due to extensive network configurations that then need to be recreated from scratch.

Does anyone have any insights are what/where we might find the cause or resolution?
ASKER CERTIFIED SOLUTION
Dimarc67

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