Windows 2008 R2 - High memory on lsass.exe

Question

Windows 2008 R2 fully patched VM with 8GB of RAM and 4 vCPUs. Machine is a DC and file server.
Had an issue that just came up where lsass.exe will start sucking up memory. It gets to the point where the machine is almost not usable. The only way to get everything back in check is to reboot.
I just rebooted a little bit ago and I'm watching lsass.exe slowly start sucking up more and more memory. I'm not sure how to tell where the memory is being used and then how to remedy it. This machine has run fine as a DC/file/print server for 3 years.
Something has happened in the last week that is making it mad. 

Answer 1

Hi,
Firstly, have you typed an invalid IPv6 subnet mask in the Active Directory Sites and Services snap-in on that Windows Server 2008 R2 DC? If yes, please refer to the KB below:
The Lsass.exe process crashes on Windows Server 2008 R2-based domain controllers
If not, I would recommend you perform a virus scan on your DC and run the Performance Monitor's Active Directory Data Collector Set on that domain controller while the problem is occurring to find the root reason. To run the Active Directory Data Collector
follow these steps:
1.Run ”Perfmon.msc”and then press enter.
2.Expand Data Collector Sets > System.
3.Right-click on Active Directory Diagnostics and then click
Start in the menu which appears.
Once the report has compiled (The default setting will gather data for the report for 300 seconds, after which it will take an additional period to compile the report.), view reports which will show details of potential problems which need to be investigated
as possible causes.
Best regards,
Susie