How to resolve Exchange 2010 Mailbox Deletion issue in DAG

Introduction

When a mailbox database in Exchange 2010 SP1 is decommnised we would like to delete the database from the server. What we have noticed in Exchange 2010 SP1 that there are issues while we delete the database.In the scenario discussed below there are multiple copies of the database in seperate servers in a DAG configuration.

Problem during Mailbox Database Deletion

A mailbox database cannot be deleted if it contains mailboxes. You have the either delete the mailboxes or move all mailboxes to another database before you can delete the mailbox database.When you delete the mailbox database it gives the error below.

But actually there is no mailbox export requests that is in place that is causing the issue.

Resolution for Mailbox Database deletion issue

We will first go throug the steps on how to delete the mailbox and then provide the solution.

i. Firstly open the Exchange Management console (EMC) go to Organization Console > Mailbox. We will delete Mailbox DB04. In our environment we have 3 servers in a DAG configuration. The servers are TEMEXGMBX01,TEMEXGMBX02,TEMEXGMBXR01. The database DB04 is mounted on Server TEMEXGMBX02. As shown below.

ii. Click on the database in the top pane and right click as shown below.

iii. Click on Remove. You will get the prompt below.

iv. Below is the error message that will be displayed. The database cannot be deleted in this way as this is the active copy of the database.

v. As a result we need to remove the passive copies of the database first before we can remove the active copy. To do that in EMC we will go the Database Copies section in the pane below. As shown below.

vi. Right Click and detele the database copies on the servers that hosts the passive copies. For our case it is TEMEXGMBX01, and TEMEXGMBXR01.Click Remove.Press Yes for confirmation.

vii. The below screen will be displayed confirmin the deletion. Note the information warning that states that we have to manually delete the files that contained the mailbox data and logs.

viii. We will do the same steps to delete the other database copy which is in the remote site. You ,might encounter the below error messgae while doing the delete if you have tuned on circular logging.

ix. To turn off circular logging follow the steps below. Right Click the database on the top pane and click on Properties.

x. The below dailog box will be shown. Uncheck Enbale Circular logging.

xi. Once the Circular logging in disabled you will be able to delete the passive copy of the database in server TEMEXGMBXR01 as shown below.

xii. EMC now will show the below with only the active database copy for DB04 remaning on server TEMEXGMBX02. As shown below.

xiii. Make sure you go and delete all the Database files from the passive servers TEMEXGMBXR01 and ,TEMEXGMBX01. Determine the drive location of the database and delete the EDB and LOG directories as shown below.

xiv. Now we will focus on the active copy of the database deletion. When you Right click the active copy of the database DB04 and delete you will get the below error message, as shown below. You will get this error even if you restart Information Store and dismount the database. This is software bug in Exchange 2010 SP1 and we will give solution to this in the next step.

xv. To remove the databse we will need to remove the Active Directory object of the database. Open ADSIEDIT and browse to the location Configuration>Services>Microsoft Exchange>Organization>Administrative Groups> Exchange Administrative Groups > Databases.

In the list of the databases delete the database DB04 as shown below.

xvi. Once the database entry in the ADSIEDIT has been removed it will not display DB04 mailbox database in the EMC anymore as shown below.

xvii. Now we can safely delete the EDB and LOG folders for the mailbox database from server TEMEXGMBX02. There may be issues deleting the files if they are locked by the Microsoft Exchange Information Store Service. Restarting the service will unlock the files and they can be deleted.

Conclusion

We can conclude the from the above the Mailbox deletion process has some issues in Exchange 2010 SP1 and a workaround like above will ensure that the storage on the server is fully utilized.