Redistributing users in Exchange 2010 databases – Part 1

-Authored by Achinta Chatterjee (link to Linkedin Profile)

Introduction

The document will describe a situation where you have a space problem in your Exchange server and your database size is growing and you have limited space remaining on all your Exchange databases. What are the steps an administrator should follow to redistribute users in your exchange servers databases.

The document is divided into two parts. The first part describes the first method and part of the second method.

Factors causing database sizes to increase

a. Users sending and receiving large amount of emails daily.

b. Archiving software not working as designed.

c. Growth of database not properly monitored or managed

d. Number of deleted items kept on mailbox databases

e. Number of deleted mailboxes kept on databases

f. Online compact of database not taking place.

g. Whitespace reclamation not working on Exchange databases

To prevent the problem of database size increase you need to have regular health checking of the servers in place and proper monitoring software installed for your Exchange Mailbox servers. However once we are in a production environment and are in a situation of space constraints we need to apply the methods described below.

Methods of Mailbox redistribution

I. Move entire Database to a storage with more free space

II. Create new database and move users

Move entire Database to a storage with more free space

This is the best and easiest approach of space reclamation. However in Exchange 2010 the process involves downtime the hosted users of the database and hence its not a popular choice. Steps to move entire database is below.

1. First we need to create 2 folders preferably in separate drives with enough free space and larger size that your previous storage, one for the EDB database and the other for Logs. Note you need to create the drives in all servers where the database will be hosted with the same drive letter (ie on all DAG members).

2. Schedule a downtime preferably after office hours as all users hosted in the database will be affected. The users will not receive any emails during this downtime and will not be connected to Outlook online mode or OWA and the Exchange database will be unavailable.

3. If your database is part of a DAG, dismount the database on all copies.

4. Open Exchange Management shell of one of the mailbox servers type in the command to move the database

Move-DatabasePath -Identity ‘MBX DB1′ -EdbFilePath ‘C:\MailboxDB\DB1\MBX_DB1.edb’ -LogFolderPath ‘C:\MailboxDB\DB1_Logs\’

Identity – This is where you give the name of the database that you will be moving

Edbfilepath - Give the path of the new Edb file along with the name of the new Edb file.

Logfolderpath – Same as the name, you just need to give the folder path.

The database move might take a while depending on the size of the data we are moving.

5. Once the database move is completed we need to focus on the other Nodes of the DAG for this database. What we will do is to copy all EDB and Log files to the target folder on all DAG members. Note again that the folder name on these DAG members must be the same.

6. Once all data on all DAG members have been moved to the new folder with lots of free space we are almost done. We need to mount the database and wait for the synchronization to take place between the database copies.

7. Once all the database is online user will be able to send and receive emails and connect to Outlook online mode and OWA to their mailboxes.

Create new database and move users

When you have a space problem and you do not want a downtime for users to redistribute them you follow the method described below.

Steps to redistribute users in the Exchange databases

A. Create a new database

B. Testing the new database

C. Move users to the new database in suspended mode

D. Complete move after peak hours

E. Check disk space and database deletion

A. Create a new database

i. To create a new database you need to first decide on which LUN volume you are going to create the Database. Choose the volume with more space available.

ii. From EMC, expand “Organization Configuration” > right click on “mailbox” to create new Mailbox Database

iii. Provide an appropriate Name for the Database and initially choose the server (later, once DB is created you must add this database to remaining servers in the DAG”

iv. Do give the drive name you already decided in the beginning and keep the selection on “Mount this database”

v. Click New and Finsh

vi. If the database doesn’t get mounted, use the EMC to mount the database.

vii. Next step is to add this new created Database into remaining servers in the DAG.

Right click on the newly created Database. Click on “Add Mailbox Database Copy”

Click “Browse’ to add the server names one by one in DAG

viii. If the Database in those servers in DAG found to be suspended, do resume by right click on the database.

ix. If you have several third party applications that a polling the Exchange database for information you need to run the commands like below to make the service accounts for the application retrieve data from the database.

For eg.

For Blackberry:

Get-MailboxDatabase | Add-ADPermission -User “BESAdmin” -AccessRights ExtendedRight -ExtendedRights Send-As, ms-Exch-Store-Admin

x. Start backing up the new database.

xi. Creating a Journal database. If you have enabled journaling on your database you need to create a separate journal database.

Once create set the Journal database inside the newly created Database properties as shown below.

Conclusion

This marks the completion of the new database creation process and end of part1. Please refer to the next article “Redistributing users in Exchange2010 databases – Part 2″ for the steps of complete the user mailbox redistribution.