Discovery: Virtual Servers vs Virtual Machine Instance

[kmlutz]

Hello All,

We have recently rolled out Discovery to our production environment.   We are starting with our main data centers and mostly targeting infrastructure items such as servers.

We are comparing the results from Discovery to our homegrown CMDB.

One thing we have noticed relates to "virtual" servers and vCenter.

In our homegrown system, the team has entries listed as virtual servers but when Discovery collects the data on these entries - they are listed only as a Virtual Machine Instance and have no record in the virtual server class.

I have reviewed the WIKI and it seems like it may have to do with how these servers are created within vCenter...possibly because a template is used to "build" this entries.

Can someone provide a specific distinction between a virtual server and virtual machine instance and how Discovery makes that distinction?

Thanks.

[amit_dhuleshia]

Kurt,

Virtual server is the actual machine (e.g. ESX server) that hosts the vm instances. So, for a virtual servers there will be many vm instances. All of this is discovered through the vCenter Probe. Here is the schema map for the virtualization server.

Hope this helps!

[kmlutz]

Hello Amit,

Thank you for the information but I still miss a connection here.   Where does the Virtual Server and VMware Virtual Machine Instance come into play?

Here is what I am trying to understand and don't see it from the schema above.

Windows Server XYZ is virtualized by ESX Server 123.   The flag "Is Virtual" is checked on that Windows Server.   So that would match to what is on the schema above.   On Windows Server XYZ it instantiates a VMware Virtual Machine Instance with the same name but in this other class.   That seems "normal."

What I have seen in the review of the data is cases where there is a VMware Virtual Machine Instance but no virtual server.   How can there be a VMware Virtual Machine Instance without the Virtual Server?

[amit_dhuleshia]

Let me see if I can clarify with an example from above.

1. The windows server will be in cmdb_ci_win_server (Windows Server) table and the is virtual field is true. This is not discovered by the vCenter probe, but by ip discovery.

2. There will be an entry in the cmdb_ci_vm_instance table (Virtual Machine Instance). This is discovered by the vCenter probe.

3. There will be an entry in the cmdb_ci_esx_server table (ESX Server). This is discovered by vCenter probe.

The relationships are maintained through the cmdb_rel_ci. The relationship between the Windows Server and Virtual Machines Instance (Instantiates). The relationship between Windows Server and ESX Server (virtualized by). The relationship between virtual machine instance and esx server (registered on).

Hope this helps.

[Pramod Vaidya]

Hi Amit,

can you explain this in context of Azure?

i mean relationship between cmdb_ci_azure_vm(discovered by web service based discovery) and cmdb_ci_win_server (discovered by IP   )