Hi,
Do I need to stop Wsus service on old server?
No, we do not.
As mentioned, it shows multi-user, is it same as the following screenshot:
I get Server is in single user mode.
Could we show the detail information about sing user mode? where we see this mode, if possible, please show the screenshot.
Here is the article, just for reference:
https://techcommunity.microsoft.com/t5/core-infrastructure-and-security/configuring-multiple-software-update-points-in-a-configmgr-2012/ba-p/322922
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