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System Center: Use the right tool for the right job

  • Artikkeli

This post isn’t really about Lab Ops as it’s more theory than Ops, but before I dive in to the world of what you can do with System Center I wanted to stress one important concept:

Use the right tool for the right job.  

That old saying that when you have a hammer everything looks like a nail can harm your perception of what SC is all about.  Perhaps the biggest issue here is simply to have a good handle on the suite, which is not easy as traditionally many of us will have been an expert in just one or two components (or whole products as was). So here’s how I think about this..

  • Virtual Machine Manager controls the fabric of the modern virtualized data centre and allows us to provision services on top of that
  • App Controller is there to allow us to control services in Azure as well as what we have in our datacentre
  • Configuration Manager allows us to manage our users, the devices they use and the applications they have. It can also manage our servers but actually in the world of the cloud this is better done in VMM
  • Then it’s important to understand what’s going on with our services and that’s Operations Manager. 
  • Rather than sit there and watch Operations Manager all day, we need to have an automated response when certain things happen and that’s what Orchestrator is for.
  • In an ITIL service delivery world we want change to happen in a controlled and audited manner whether that’s change need to fix things or change because somebody has asked for something.  That’s what Service Manager is for and so if something is picked up by Operations Manager that we need to respond to this would be raised as an incident in Service Manager which in turn would automatically remediate the problem by calling a process in Orchestrator which might do something in Virtual Machine Manager for example.

The reason that SC is not fully configured and integrated out of the box is simply down to history and honesty. Historically SC was a bunch of different products which are becoming more and more integrated.  Honesty comes from the realisation that in the real world, many organisations have made significant investments in infrastructure and its management which are not Microsoft based.  For example if your helpdesk isn’t based on Service Manager then the other parts of SVC can still to large extent integrate with what you do have, and if you aren’t using Windows for Virtualization or your guest OS then SC can still do a good job of managing VMs, and letting you know that the services on those servers are OK or not as the case maybe.  

Another important principle in SC is that it’s very important not to go behind the back of SC and use tools like Server Manager and raw PowerShell to change your infrastructure (or fabric as it’s referred to in SC).  This is important for two reasons, you are wasting your investment in SC and you have lost a key aspect of its capabilities such as it’s audit function.  Notice I used the term “raw PowerShell”; what I mean here is that SC itself has a lot of PowerShell cmdlets of its own however these are making calls to SC itself and so if I create a new VM with a Virtual Machine Manager (VMM) PowerShell cmdlet then the event will be logged. 

There’s another key concept in SCV and that is “run as” accounts so whther I am delegating a control to user by giving them limited access to an SC console or I am using SC’s PowerShell cmdlets, I can reference a run as account to manage or change something without exposing the actual credentials need to do that to the user or in my script.

Frankly my PowerShell is not production ready, some of it is deliberate in that I don’t clutter my code with too much error trapping and some is that I am just not that much of an expert in things like remote sessions and logging.  The point is that if you are using SC for any serious automation you should use Orchestrator for all sorts of reasons:

  • Orchestrator is easy, I haven’t and won’t post an update on getting started with Orchestrator because it hasn’t really changed since I did this
  • It’s very lightweight  - it doesn’t need a lot of compute resources to run
  • You can configure it for HA so that your jobs will run when they are supposed to which is hard with raw PowerShell.
  • You can include PowerShell scripts in the processes (run books) that you design for things that Orchestrator can’t do
  • There are loads of integration packs to connect to other resources and the these are setup is with configurations which have the credentials in to those other services so they won’t be visible in the run book itself.
  • you have already bought it when you bought SC!

Another thing about SC generally is that there is some overlap, I discussed this a bit in my last post with respect to reporting and it crops up in other areas too.  In VMM I can configure a bare metal deployment of a new physical host to run my VMs on, but I can also do server provisioning in Configuration Manager so which should I use? That depends on the culture of your IT department and  whether you have both in production.  On the one hand a datacentre admin should be able to provision new fabric as the demand for virtualization grows on the other hand all servers be they physical or virtual should be in some sort of desired state and CM does a great job of that.  It all comes back to responsibility and control if you are in control you are responsible so you need to have the right tools for your role. 

So use the right tool for the right job, and after all this theory we’ll look at what the job is by using SC in future posts