DWH Current VM Capacity Fact - Provisioned Capacity discrepancy

[tony_dt]

Hi,

I have a simple report that I am using and it will be of great benefit but unfortunately the data is incorrect. I am using source "VM Capacity->Current VM Capacity Fact->Provisioned Capacity GB" for my report.

The problem is that if compare the value with reality the numbers are slightly less. If I examine the value in "Datastores->Provisioned Capacity" the numbers do not match. If I grab the information from Vcenter the values match OCI but not the source above in DWH.

Is there another source I should be using? I want the true Provisioned Capacity.

[moechnig]

Per-VM provisioned capacity numbers in vm_capacity_fact should reflect the size of each VM's VMDKs plus other overheads such as swap files.  Each data store will contain some amount of overhead on top of the sum of provisioned capacity for VMs on that data store. 

To dig into this in more detail, we would need to know the other columns you've included in your report.  This will determine which overheads Cognos will include.  It would also be helpful if you could specify what it is that you're comparing the OCI numbers to. 

If you want to look more closely at this yourself, I recommend that you also include the numbers reported in the OCI Java GUI in your analysis.  It's much easier in my opinion to tell exactly what it is that you're measuring in that interface than it is in Cognos or SQL.  This will help you determine whether there's a gap between your report and OCI's understanding of the environment, or between OCI's understanding and reality. 

[tony_dt]

Thanks for the input.

1. I have enclosed screenshot of the report and the microview, but columns are Host Data Center|VM Cluster|Datastore|Actual Capacity GB|Provisioned Capacity GB

2. The OCI Microview is Inventory->Datastores. The valus is correct in the OCI Microview and matches the VM Environment.

3. Provisioned Cpacity is off by 40GB reported by "Current VM Capacity Fact->Provisioned Capacity GB".

[moechnig]

Tony, I don't see the attachments here so perhaps they were stripped before your message posted to the web site. 

Is the DWH number for actual capacity 40GB over or 40GB under what you would expect based on looking at the web UI? 

It might be worth noting that "actual" in the VM mart is what we might call "Used" or "Consumed" in some other locations.  It's the amount of capacity consumed from a thin-provisioned data store. 

[graemeo]

If you're not trending the data over time, you can use the Inventory data mart which should match what you see in the thick client.