Today we worked on installing a new server at an office that has around 50 users. We planned out and deployed a server migration from Server 2008 R2 to Server 2019.
All worked well, FSMO, DHCP, DNS, everything moved over without a hitch. After modifing the login script to recognize the new file server, all users were able to login without any problem and access files.
That all changed about an hour later. A network connection was disconnected from the new server. And ever since then, the computers have slowed to pas a crawl.
Like it literrally takes 15-20 mins just to LOG IN!
Once logged in, you simply can't click any applications or even the start menu. They aren't locked, just every operation takes minutes when they should be mili-seconds.
I started investigating. One issue I found was the GPO objects didn't move from the old server. So when I tried to modify them in the GPO manager, it gave errors saying it couldn't be found. So I copied them out of SYSVOL on that old server. Great. I was now able to edit those GPOs.
I cleaned up some DNS entries, but I cannot find anything in the event log of any of the servers to indicate any problems. Since the workstations are soooooooooooo slow, I can't even open the event viewer to see what is going on. Every command I send it, times out. I can't find any errors in DNS or DCDIAG.