@Christian_Dahlqvist Thanks for your help. I have one last thing to ask.
I am given 3 medium sized machines. with 7.5GB RAM. I have read the documentation which says the memory should not be less than 8 GB. I have been running Elastic stack on single node on similar(7.5 RAM) sized machines.
If I go with the same size of vms for all three nodes. Do you think I will have issues going forward. In my prod env I will be monitoring approx 500 servers logs for one year.