Friday, June 28, 2013

Cisco UCS 101

Hi All,

I've started to use a Cisco UCS for compute and while it is a VERY cool platform it's like I'm having to re-learn what it means to administer servers.  When I first started using it I thought, "Who was the crazy person who came up with this?!", but the more I use it the more I'm really starting to like the flexibility it gives you!

This is going to be a REALLY entry 101, more like a 1, but I felt as I learn the UCS more I'd continue blogging about it.  My UCS is currently being used, so I won't be able to show you everything, but I'll do my best to explain.

Once you're inside UCS Manager you'll see a bunch of tabs in the upper left hand corner.  Click on the Equipment tab.

Here you'll see all of the hardware currently being administered by your fabric interconnects.  Now here's where things get a little different.  I thought, "Cool, just highlight one of these servers and I can pop in a CD or direct it to an ISO image."  Well, it doesn't quite work that way.  Click on one of your servers and take a look at the right hand of the screen.

Holy Macaroni!  When I first saw this I was majorly overwhelmed and this is just the Equipment tab!  Let's break it down to the basics.

1.  Associate Service Profile.  Sorry, mine is grayed out cause it already has one, but if you have hardware that's either new or not in use it probably won't be grayed out.

2.  Service Profile.  I'll go into this a bit more in a minute.

3.  KVM Console.  Awwwww, finally something I understand!  This will give you console access to your machine.  If you don't have a service profile attached, this will be grayed out for you.  HUH?  So how the heck do I log onto this thing to install ESXi, Windows, Linux or whatever?!

4.  Configured Boot Order.  This is very handy.  This tells the equipment how you'd like to boot it.  So here my first boot device would be a CD-ROM, and then iSCSI.  If you have local disks in your system you can boot from local disk, or SAN, or whatever!  The UCS is super flexible this way.  Remember if you don't have a service profile attached, this won't be there.

So now that we have a bit of information about the server itself, what the heck is a service profile and what does it have to do with anything?  The way you give a personality to individual blades is by creating a service profile.  Think of it this way.  The equipment is the android body.  It has all of the capability to walk and talk, but without a brain or connections to that brain it's just a lifeless shell.  Think of the service profile as all of the connections from the brain to the body.  Here you create the mapping of connections, network, storage, etc.  Once you have it all mapped out, you assign it to one of the blades.  So remember arrow number 2 in the image above?  Let's click on the Servers tab and then click on policy ESX5.1-3.

Take a look at the left hand side.  You can create all of the service profiles you want, they don't have to map one to one with a piece of hardware.  You can see a bunch of service profiles that have been created.  When I click on ESX5.1-3, I get a ton of information about the profile.  If I click on the Boot Order tab I can see how this profile will boot.  If you take a look this profile will first boot off the CD-ROM and then iSCSI disks, but that is completely up to you when you're building the profile.  The neat thing is you can map an ISO image to the CD-ROM, so you don't have to use physical media.

The great thing about this is you can create a bunch of profiles, associate them to iSCSI LUNs, a blade and install whatever OS you want on that LUN.  Next you can disassociate that profile move it around to other blades or just have it ready when you want to use that OS.  So for example, you create 3 profiles:  Windows 2008R2, ESXi 5.1, Linux.  I can associate or dissociate at will, which makes this SUPER cool in a testing environment.

So that's my Cisco UCS 101 for now.  There are a TON of things you can do here and I've barely scratched the surface, so be on the look out for a lot more UCS blogs.

Until Next Time!

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