Firstly, welcome to using Communities and VMware in general!
By "single Linux server" I am assuming you mean a single ESXi host running on a physical server with 6 VMs on it.
To access control of these host and the VMs (on the ESXi host via SSH) you will need to enable incoming SSH connections the steps for doing so is outlined here (for ESXi 5.1):
But to access this you will need the vSphere client for your local computer to access this GUI interface/client:
This *client* is more than just a GUI, it is feature-rich and you can do near anything between this and the CLI.
If you are unable to install this due to the security reasons specified (ask an administrator if you can install this, it will things a lot easier) then if you have physical access to the server you can enable SSH via the Direct Console User Interface (DCUI)(e.g. plug a monitor, mouse and keyboard into it), you can also access the CLI here.
Alternatively if the RHEL VMs are functional and the necessary ports open, you may be able to access and manage them directly via SSH.
Also, regarding 'vCenter' this is basically just another client/GUI for managing multiple hosts, if you have only one host (on one physical server) then this is likely not implemented in the environment. (this can be connected to using the vSphere client in the same way you connect directly to a single host using the application noted above)
-o- If you found this comment useful please click the 'Helpful' button and/or select as 'Answer' if you consider it so, please ask follow-up questions if you have any -o
1 person found this helpful
I agree with everything Bobkin said, and also welcome you to VMware. I hope you stay!
To start with VMware, you first interact with the DCUI (Direct Console User Interface). This gives you the ability to change the TCP/IP stack on the host. You're probably there already but just checking. Then from a remote computer type the IP address into the browser that you see on the ESXi's DCUI. This allows you to download the vSphere Windows Client or to interact with the Web Client. Even if you are on something as strict as a sensitive government network, this would still work because you don't need web connectivity: the ESXi has these downloads built into it.
Installing vCenter is a whole different subject. You would be using the VCSA (vCenter Server Appliance) which is built on SUSE Enterprise Linux. The ways to install this can be profoundly different depending on which version you're using. But unlike the Windows vCenter installation which require putting the installation CD into the hypervisor itself (or attaching it through the datastore), you just burn the files onto a CD and then put it into your workstation. You will need to download them from your VMware account which means that they will not be made available from the hypervisor like the vSphere client.
However, you don't need vCenter to activate shell access, you just need to go into the configuration for your host and change the settings under your host's security profile like Bobkin said.