had something to do with the fact that my vsan cluster ESXi hosts did not have DNS setup. I neglected to set DNS after imaging them using VIA. I don't know how that affected nsx-manager memory, but somehow it did. After I realized I had missed a step in my setup procedure and configured the resolv.conf, my nsx-manager is using aroud 84% memory and working fine, not crashing anymore! Thanks for the input, I can't believe I managed to build a full vSAN cluster without something failing with no DNS configured I had been configuring my hosts by hand and then moved to using VIA and somehow had the impressions that I was feeding the DNS settings into it, but it does not, so problem solved.