Why does PrepareAd create New groups Eg: Exchange Servers1

Why does PrepareAd create new groups with suffix 1 Eg: Exchange Server (1)?

Recently one of my client asked me why does Setup.com /PrepareAd create new groups with suffix 1 Eg: Exchange Servers1 or Exchange Recipient Administrators1. I did research on that and came to know something  new so thought to share that.

Before we jump to any conclusion, we must be aware that when we run Setup.com /PrepareAd It adds new universal security groups that are within the Microsoft exchange security groups OU to the otherWellKnownObjects attribute stored on CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=XYZ,DC=com container.

Exchange recipient administrators1 group or any other group with suffix 1 will be created within the Microsoft exchange security group only incase when we run Setup.com /PrepareAd and one or more universal security group is present within the Microsoft exchange security groups OU but its reference not present in Otherwellknownobjects attribute stored on the CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=XYZ,DC=Com container.

Lets suppose if we delete a group Exchange servers from Active directory users & computers. However It will be still present in the Otherwellknownobjects attribute stored on the CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=XYZ,DC=com container.

Now to get Exchange servers group we will have to run Setup.com /PrepareAd but it will failed because the OtherWellKnownobjects is still having the information of the Universal security group which has been deleted now and we will get the almost similar error.

Organization Preparation……………………. FAILED

     The well-known object entry B:32:A7D2016C83F003458132789EEB127B84:CN=Exchange ServersADEL:bdd7875e-aa8e-410c-b8a3-3b53d8a2b7eb,CN=Deleted Objects,DC=XYZ,DC=COM of the otherWellKnownObjects attribute on container object CN=Configuration,DC=XYZ,DC=COM points to an invalid DN or a deleted object.  Please remove the entry and rerun the task.

To fix the above error we will have to delete the references of deleted groups from Otherwellknownobjects attribute stored on the CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=XYZ,DC=com container.

Above steps are mentioned in the following TechNet article

http://technet.microsoft.com/en-us/library/bb288907%28EXCHG.80%29.aspx

Now by mistake if we delete the references to the groups which are still present within Microsoft exchange security group from the otherWellknownObjects attribute and we run Setup.com /PrepareAd, It will create the groups Eg. Exchange recipient administrators1 or Exchange view only administrators1 for groups which are still present within Microsoft exchange security group.

Please let us know your valuable feedback or if you have any questions.

Thanks

Team MSS

Exchange Server 2007, Exchange Server 2010