What is the best practice when migrating from one vCenter to another to resolve the entity duplication in BMC TrueSight Capacity Optimization?

The best practice recommendation are:

1. Create a new vCenter Extractor Service ETL to collect data from the new vCenter, that use the same entity catalog of the old ETL and new hierarchy rule.

2. Stop the old ETL and start the new one

3. Let the new ETL run and import the new duplicate entities into CO

4. Use the standard CO Reconciliation process to reconcile all of the entities between the old vCenter and the new vCenter

5. Delete the old ETL and the related Hierarchy rule.

It is expected that the following entities will be looked up properly without creation of duplicated entities

• VMware Virtual Host

• VMware Datastore

This is because hosts and datastores have a UUID value in the lookup that is unique across the environment (not just within a single vCenter) so these entities can be automatically mapped together after the migration.

NOTE: For VMware Hosts there is a plan to remove the UUUID as a strong lookup which means that in a CO 10.3 or 10.5 version that includes a Cumulative Hot Fix (CHF) with that change VMware Hosts will need to be reconciled after a vCenter migration (the same as Virtual Machines).  Contact BMC Technical Support for more information regarding this change.

The following entities will need to be manually reconciled via the reconciliation UI:

• VMware Virtual Machine

• VMware Virtual Clusters

This is because VMware VMs and clusters have lookup values that are unique within a vCenter (not unique across the environment).
In detail, following VMware reccommendation, the lookup fields used for the VMs are (n this order)

• PARENT_VCUUID && VMW_VMREF or

• PARENT_VCUUID && VMW_VMREF or

• UUID

So, when you migrate the VMs from a vCenter to another one, both the fields will change and this create duplicated entities.

The entity reconciliation can be run while the vCenter Extractor Service continues to run.
There will be some periodic errors when they both run at the same time (since the reconciliation process moves the data from the entities imported by old the to the entities imported by the new one and then deletes the new entity), but beyond the Diagnostic Alert messing the impact should be negligible.

It is recommended to deploy this CHF

• CHF9 or newer for CO 10.0

• CHF9 or newer for CO 10.3

They contains the fix for two important defect that can an impact during reconciliation process

• QM001887160: Entity reconcile task ends after the first failure.

• QM001961626: Reconcile: data older than 30 days are lost

In general it is a best practice before running a reconciliation to apply the latest CHF package or review the CHF README to see if any reconciliation fixes are listed as being corrected.
(see Cumulative Hot Fixes for TrueSight Capacity Optimization (CO), CO Gateway Server, and CO Agent, and CO Perceiver)

In general the reconciliation process via the UI after a vCenter migration is relatively easy to implement and yields the expected results.

If there are any concerns or difficulties contact TSCO Technical Support.