So I wanted to talk on best practices for your Service Console, what it’s for, and why and how to make it redundant. As that’s a lot of information, we’ll break it out in some parts.
This first part we’ll talk about what the service console is, and what it does.
So what is the ‘Service Console’? It is the “Console Operating System” that is responsible for user interaction with ESX. In the full ESX 3/3.5 (as in not ESXi), the service console is a VM that is based on RHEL 3. In fact this is often what keeps folks confused and arguing that “ESX is just Linux”. However, this is very much not the case. VMware has also tried to do everything possible to deemphasize the use of the service console, and, in the ESXi release, and perhaps future releases, it will go away completely, to be replaced by things like VIMA (VMware Infrastructure Management Assistant).
What’s it do this service console? I suppose my single line above wasn’t quite a good enough, but that is more or less what it is responsible for: User interaction with ESX. This is a bigger task that it first appears when you consider the various ways one can communicate with ESX:
- Command Line Interface (CLI)
- SSH Access
- Web Management (this includes SOAP, and the other various API’s)
- Using the VMware Infrastructure Client
- Communication with Virtual Center
The Service Console is also responsible for keeping this communication secure. This is done in several ways as well.
- ESX Firewall (iptables)
- SSL to the web services
- Standard Linux authentication methods (keep your eyes open for a future article on getting ESX to talk to AD)
The last two things the Service Console does are manage access to ‘non-critical’ hardware, and provide support applications. Interesting, no? Lets explore those further.
What is ‘non-critical’ hardware? ‘Non-critical’ hardware is anything outside the Core 4 (Memory, Disk, Networking, CPU), things like serial ports and cd-roms. This keeps the VMKernel light and agile to better support your VM’s.
The last bit is support applications, and these are simply applications, like vm-support, or the esxcfg-* set of commands that allow you to keep the host running in tip top shape. With ESXi, these are handled either via the VIMA, or rCLI, which can both be downloaded from VMware’s site.
So, we’ve now covered what the Service Console is, and what it does. Next go around we’ll cover the why and how of making it redundant.