Why, when discovering a Virtual machine instance, does discovery create a "Computer" record and a "Windows Server" record as well as the "Virtual Machine Instance"?

lharrison · ‎11-07-2014

When discovering VMware using ServiceNow Discovery, I get several records created for a single device.

Sometimes it can be a Computer, Windows Server and a VMware Virtual Instance or other times it's just the Windows Server and VMware Virtual Instance records.

Excuse my ignorance if there's an easy answer to this.

Thanks, in advance

Larissa

anders9 · ‎11-12-2014

Hello Larissa,

There are two sides to the discovery here. One is the vCenter discovery that will connect to the vCenter API and collect information about the VMware environment such as ESX servers, resource pools and virtual machine instances. Generalising a little the virtual machine instance is a VMware configuration which could run an operating system and contains a UUID which is a unique identifier.

The other side of discovery here is the "operating system" discovery and in your case when discovery finds the Windows server running extracting information such as os version, cpu, ram, etc. If it's a VMware environment it will match the serial number with the UUID and link the two CIs together.

Finally - I'm wondering if the case that you see a "computer" as well as a "windows server" is due to that the Windows Server table is extended from the computer table? I would expect these CIs to have the same "sys id" - so they're basically the same record.

Hope this helps!

Regards,

Anders

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anders9 · ‎11-12-2014

Hi Larissa,

I agree that the table extensions can be a little confusing - and if you add the column "Class" to your list view on the computer table you can see the specific table they belong to. So you don't want to delete these records - but you might want to change the filter of what is displayed when you look at the "Computer" records so you don't see any server records etc.

The Virtual Machine Instance record is a VMware component containing information about what VMware knows about the virtual machine. It can be used by ServiceNow Orchestration to manage actions such as start, stop, take snapshot etc. So it's a little different to the "Windows Server" record which is more from the operating system point of view.

It might look like the Virtual Machine Instance and Windows server CI is the same thing - they are related but they're different.

You might want to look at refining the reference qualifier when selecting a CI for change - it's probably unlikely that anyone would raise a change against a Virtual Machine Instance - so there can probably be filtered out together with DNS, IP address, etc.

Regards,

Anders

Daryll Conway · ‎11-12-2014

Can you tell me how information is filtered out when discovering Virtual Machines? I'm looking to add IP address back in as it isn't currently being picked up

anders9 · ‎11-17-2014

Sorry for the late response here Daryll... I would expect IP address to be picked up from discovering the Windows/Linux server - and not from discovery of the vCenter information. Could you expand on the issue you are experiencing?

Daryll Conway · ‎11-18-2014

I've located my problem it's actually a credentials issue with CIM. I'm trying to get ESX servers to be discovered but all I get back currently is the serial number and nothing else.

anders9 · ‎11-19-2014

Hey Daryll - you should get (most of) the ESX server server details back from the vCenter probe (see tag hostSystems) e.g.

vendor, ip, hostname, cpu info, model, vendor, ...

Only the serial number is gathered using the CIM probe.

Regards,

Anders