0

We have a number of identical Windows Server 2019 systems and are noticing that on one particular server the DNS Client service sometimes starts using excessive amounts of memory. So far we've not been able to figure out what triggers it, nor how to clear it without rebooting the server. Normal usage is about 2MB. Once it starts "leaking", it adds about 2MB every hour until we reboot the system.

enter image description here

ipconfig /displaydns shows just 8 entries, as expected. ipconfig /dnsflush and ipconfig /registerdns seem to have no effect. Apparently Windows does not allow restarting the DNS Client service any more, so a reboot is the only way we can resolve it currently.

System Details:

  • 3 physical Dell PowerEdge servers, each hosting 2 HyperVisor WS 2019 VMs
  • The servers host web services on a corporate network for internal use only
  • None of these servers are domain members or controllers
  • IPV6 is disabled
  • All of the servers are continually communicating with each other via HTTP

I'm wondering if it could have something to do with the fact that the systems use the corporate DCs for DHCP and DNS, but aren't members? The DNS seems to work just fine though.

This question from 9 years ago is similar, but doesn't seem to provide any resolution. Any ideas?

Chris Olsen
  • 153
  • 6
  • If the DNS Client is using 250 MB of memory and that represents 63% of your total memory, you have a memory-starved system. Your solution is to add more memory to the VM. Otherwise, there is nothing that I know of to optimize or modify the built-in DNS Client. – John Hanley Mar 29 '21 at 17:22
  • *Total* memory usage is 63% of 4GB. Dnscache.exe will just keep growing (1GB the first time we noticed it). – Chris Olsen Mar 29 '21 at 17:27
  • 1
    4 GB of memory for Windows Server 2019 would be at the bottom of what I would configure. Make certain your system is not using SWAP space. Your only options are to add more memory or open a support ticket with Microsoft. Note: 256 MB for any Windows program is not "excessive memory usage". – John Hanley Mar 29 '21 at 17:32

0 Answers0