VMware Cloud Community
MattG
Expert
Expert

FEATURE REQUEST: Keep historical data for objects no longer in use

To the best of my knowledge it appears that when objects are removed from vSphere,  they are remove from vCops.   You can still see them in the Custom UI with a blue question mark,   but all of the metrics are gone.

For example I rebuilt my cluster replacing AMD hosts with Intel hosts.   Since the servers are new objects,  I have no way of comparing the metrics to understand performance gains for the Intel servers as the AMD data is gone.

Thanks,

-MattG

-MattG If you find this information useful, please award points for "correct" or "helpful".
Reply
0 Kudos
4 Replies
gradinka
VMware Employee
VMware Employee

Hm I think you can do that, there was some property file...

I will check.

Reply
0 Kudos
mark_j
Virtuoso
Virtuoso

When you remove a object from vCenter, it does not remove that resource from vC Ops. This is the default. It is possible to make a custom change to a conf file to change this and delete a resource when it no longer exists in vCenter.. this is what gradinka was just hinting to I believe.

What you describe as seeing the blue question mark means that the resource is there, but isn't collecting metrics. This would make sense if it 1-was deleted from vCenter and 2-the resource still exists in vC Ops.

When a resource stops collecting new data in vC Ops, it doesn't treat that resource any differently that any other resource. The retention settings for a vC Ops instance applies to all metrics of all resources in vC Ops. What I would expect to see is that a resource that is no longer collecting will initially "appear" to have just a long a past metric history as other, but as data ages out that historical data is lost off the backend. Eventually, after the retention period equals the amount of time since the resource last collected metrics, the resource will have a blue ? AND have no metrics.

I the example you replaced hosts with different hardware. In other words, you removed an object from vCenter and then added a new object. Each object registered to vCenter get a unique identifier. This identifier is used to uniquely identify resources in vC Ops. When you replaced the host, you essentially abandoned the vC Ops resources and the metrics will age out of the system as per retention settings. The new host will appear a new resources and start collecting metrics from scratch.

If you want to compare performance at a host level, you'd have been better off running the hosts side-by-side, concurrently, to compare the metrics. By remove the old host and adding the new, you limited your comparison options and are stuck to:

A. Using old host metrics as they age out from the old host

B. Using Cluster-level metrics to gain some insight in to general host performance

C. Possibly doing some custom config of the old host resource to make it "appear" to have the same identifiers as the new hosts and pick up the new host's identify.

If you find this or any other answer useful please mark the answer as correct or helpful.
Reply
0 Kudos
MattG
Expert
Expert

Mark,

Thanks for the detailed response.   What is the retention period and can that be adjusted?   I am trying to view from 4 months ago in the Metric Graph using the CustomUI and there is no data.

Thanks,

-MattG

-MattG If you find this information useful, please award points for "correct" or "helpful".
Reply
0 Kudos
mark_j
Virtuoso
Virtuoso

The default retention period is 180 days.

See the KB for instructions on changing this:

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=200822...

If you find this or any other answer useful please mark the answer as correct or helpful.
Reply
0 Kudos