Dear All,
today I have upgraded my old Dell T420 from 48GB to 144GB of RAM to handle few more machines. The memory DIMMs are Samsung dedicated for this server. Boot was totally successful, new ram is recognized correctly and the server works like a charm except hypervisor. I have 4 VMs that I was unable to boot after upgrade. There was just an error that in cannot change the VM state. Everything get to normal WHEN I removed new RAM DIMMs.
T420 BIOS 2.4.2