I have installed vCenter Server 5.1 on a virtual machine with Windows Server 2008 R2 to manage my 2 ESXi hosts in a small environment with 15 virtual machines. This virtual machine use 5.5 GB memory on one of the my hosts. Why 5.5 GB? What's amount of memory need to vCenter Server for manage only 15 virtual machine with clustering? Does it work correctly? or it’s have problem?
Services running in this virtual machine:
1- vCenter Server
2- vCenter Inventory Service
3- vCenter Single Sign on
4- vSphere Web Client
5- vSphere Client
Have a look in the install and setup guide
If vCenter Server, vCenter Single Sign On and vCenter Inventory Service are installed on the same host machine (as with vCenter Simple Install), 10GB of RAM are required.
Same page, another GB for the vSphere Client and 2 GB for Web Client.
So you could say the minimum requirement would be around 12 GB RAM to be supported.
As to why, Java tomcat eats up quite some memory. Single Sign On, Inventory Service, vCenter Management Web Services, Web Client are all tomcat processes.
I'd recommend you take a look at the Windows Task Manager to see which processes use a large amount of memory. I could bet it's the SQL server, which usually grabs as much memory as possible. From my personal experience (which may not necessarily be a supported configuration) it should be sufficient to provision the vCenter Server with 4GB for the mentioned size, if you are low on physical memory.
I hold a bet against you :smileysilly: This sounds pretty much like an SQL Express deployment which has a limit of 1GB RAM usage anyway.
I dont have Update Manager installed on my box but guess what is eating the memory away.
Well, I guess I'll better not take that bet I installed vCenter Server on Windows 2012 with most features, i.e. the ones mentioned plus Update Manager, Dump Collector, ... and the Task Manager shows a usage of ~4GB with 2 ESXi connected hosts, but no VMs running. In addition to this, the system doesn't have A/V installed yet, so I guess a little bit more memory wouldn't be that bad.