VMware ESXi server hardware

I have a VMware infrastructure in my company and it’s time to make a hardware upgrade.

All my server are up and running and i can’t shut them down, how can i check how many slots of physical memory RAM are free? It’s as simple as running on the ESXi Shell the command:

smbiosDump

This command will list all the hardware on the server and all you need to find is the
Memory Device section an in Size you’ll see the size of the memory that is installed or it says Size: no memory installed all you have to do is count the ones that says that.