VMware Datastore entities with the same Datastore UUID from different vCenters are being aggregated in BCO

Knowledge Article

Article Number

000263530

Old Article Number

000111994

Article Type

Solutions to a Product Problem

Title

VMware Datastore entities with the same Datastore UUID from different vCenters are being aggregated in BCO

Summary

Two Datastores are seen using the same UUID across different vCenters concurrently

Product

TrueSight Capacity Optimization

Component

Capacity Optimization

Applies to

10.3

Problem

BMC TrueSight Capacity Optimization (CO) is reporting an unusual situation of VMware Datastore entities with the same UUID. There are two different vCenter and both had the Datastore active and mounted with the same UUID. The Datastore is seen as active on two different vCenter concurrently and each vCenter have I/O activity associated with the datastore.

Cause

The Datastore could have been cloned with the same UUID as the original and this causes that two different Vcenters have I/O activity associated to the Datastore at the same time.

Solution

The behavior seen in CO is that two different vCenter Extractror Services were actively updating data for a datastore with same UUID mounted in two different vCenters concurrently.

Problem symptoms include:
* There are two VMW_VMREF lookup values associated with the Datastore and they both have a current Last Activity timestamp
* Running the vSphere PowerCLI against both vCenters reveals that these Datastore entities do exist and do, on the vCenter side, have the same UUID.

This is a highly unusual situation where two Datastores have the same UUID and is being used by two different Venters concurrently, this situation could be occasioned by:

(1) It could have been the same Datastore mounted in two different Vcenters at the same time.
(2) It could have been that two different Datastores had the same UUID (possibly due to disk being cloned).

Even though it is fine to move a Datastore from one vCenter to another, it is recommend to avoid having two different Datastores concurrently with the same UUID across different vCenters, if the datastores is cloned the administrator can mount it ussing the same signature or assign a new signature, the following document from VMware shows how to manage duplicate MFS Datastores: https://pubs.vmware.com/vsphere-50/index.jsp?topic=%2Fcom.vmware.vsphere.storage.doc_50%2FGUID-EBAB0D5A-3C77-4A9B-9884-3D4AD69E28DC.html.

UUID is used as strong lookup for "Virtual Host" entities but not for "Virtual Machine" entities, this means that the strong/weak lookups are ETL and entity type specific.

To solve this problem, you must be sure that:
If there is a sign that the Datastore has been cloned and it UUID is used by other Datastore. if it is the case, the VMware admin should change the UUID when mounting the Datastore on the new vCenter to avoid data corruption from the Datastores when metrics are being collected by BCO.

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