My customer have HA edge gateway configured to size compact. Now they need more resources (ram and cpu) to edge.
I try to find some articles about it but I could not find any.
Is it possible just increasing RAM/CPU to edge gateway VM or somehow change edge gateway configuration size from compact to large?
Yes, it´s possible. You can go to the Organization VDC, Administration tab and NSX Edges. You select the NSX Edge and Modify Form Factor.
I hope it helps you.