In order to evaluate ESXi for use in test environments, I had installed it on a low end host (a DELL Optiplex GX520 desktop) and tried to run two virtual machines on it. However, when I would try to start the second virtual machine, it would throw an “Admission check failed for Memory Resource” error on me. I wasn’t able to figure out why this was happening as I had run two virtual machines with the same configuration on a host with similar resources using VMWare Server.
All that needs to be done is to modify the memory reservation in the resource allocation tab
1. Open the VMWare Infrastructure interface to the ESXi server
2. Select Configuration >> System Resource Allocation >>Advanced
3. Click on Edit Settings and edit the memory reservation and change it to 256 MB or lower (as per requirement)