Altering the vCenter VM without a Management Cluster

What do you do, when you have a virtualised vCenter VM, but you want to adjust something about it without locking yourself out of vCenter.

In my case I had a vCenter server that I wanted to adjust the memory on. To do this without locking yourself out, you should follow these steps:

1. First determine which ESXi host the vCenter VM is running on lets say its: esx7.domain.com

2. Connect using SSH to the esx7 console. (you may need to enable this in advance).

3. Run the command below to find the “vcenter1” VM’s identifier.

# vim-cmd vmsvc/getallvms | grep vcenter
80 vcenter [datastore1] vcenter/vcenter.vmx windows7Server64Guest vmx-08 vCenter Server

Here you can see it is ID: 80.

4. Shutdown the VM. At which point you’ll lose access to vCenter. Check it has stopped with this:

# vim-cmd vmsvc/power.getstate 80

5. At the command line edit the vmx file to adjust the memory:

# vi /vmfs/datastore1/vcenter/vcenter.vmx

(Change the memory directive line and save the file)

6. Now run the command to start the VM again.

# vim-cmd vmsvc/power.on 80

7. Wait for the vCenter VM to start and log back into vCenter.