Each Mailbox server installed in the organization has an
information store. The information store operates as a service and
manages the server's databases. Each mailbox database has a database
file associated with it. This file is stored in a location that you
specify when you create or modify the mailbox database.
Mailbox databases can be either active
databases or passive copies of databases. Active databases are the ones
users access to get their mailbox data and are the subject of this
section.
Understanding Mailbox Databases
Mailboxes are the normal delivery location for messages coming into
an organization. They contain messages, message attachments, and other
types of information that the user might have placed in the mailbox.
Mailboxes, in turn, are stored in mailbox databases.
When you are installing a Mailbox server, Setup prompts you to
specify whether you want to create the default mailbox database. If you
decide to create one, you can also specify its name and location. The
default mailbox database is meant to be a starting point, and most
Exchange organizations can benefit from having additional mailbox
databases, especially as the number of users in the organization grows.
There are many reasons for creating additional mailbox databases, but the key reasons are the following:
-
To provide a smaller unit of management
Additionally, when you establish database availability groups and
create copies of a database, the entire database must be replicated
from the source database to the database copies. The larger the
database, the longer the initial update process takes. During recovery,
you can restore individual databases without affecting the performance
or uptime of other databases on the system. -
To impose a different set of mailbox rules on different sets of users
Each additional mailbox database can have its own property settings for
maintenance, storage limits, deleted item retention, indexing,
security, and policies. By placing a user's mailbox in one mailbox
database instead of another, you can apply a different set of rules. -
To optimize exchange performance
Each mailbox database can have its own storage location. By placing the
mailbox databases on different drives, you can improve the performance
of Exchange Server 2010. -
To create separate mailbox databases for different purposes
For example, you might want to create a mailbox database called General
In-Out to handle all general-purpose mailboxes being used throughout
the organization. These general-purpose mailboxes could be set up as
shared mailboxes for Postmaster, Webmaster, Technical Support, Customer
Support, and other key functions.
When you create a mailbox database, you can specify the following information:
-
What the name of the database should be -
Where the database file is to be located -
When maintenance on the database should occur -
Any limitations on mailbox size -
Whether deleted items and mailboxes should be retained
Each mailbox database has a default offline address book (OAB). If you are using public
folders, there's also a default public folder database associated with
the OAB. Microsoft Outlook 2003 clients access the OAB as part of the
public folder data by using Messaging Application Programming Interface
(MAPI). Office Outlook 2007 and later clients access the default OAB
and default public folder hierarchy on your organization's Client
Access servers using Hypertext Transfer Protocol (HTTP) or Secure HTTP
(HTTPS). By default, clients inside the corporate network access the
OAB using HTTP, and clients outside the corporate network access the
OAB using HTTPS.
Exchange 2010 uses the mailbox provisioning load
balancer to automatically select a database to use when you create a
new mailbox and do not explicitly specify the mailbox database to use.
As the name implies, the purpose of the load balancer is to try to
balance the workload across mailbox databases in the organization.
Although the load balancer uses multiple criteria to try to determine
where a mailbox should be created, the selection criteria does not take
into account the proximity of the Mailbox server on which a database is
stored to the computer or computers used by the user. In a large
organization with multiple Active Directory sites, you typically will
want a user's mailbox to be located on a Mailbox server in the same
site or in an adjacent well-connected site.
Creating Mailbox Databases
You can create mailbox databases using the New
Mailbox Database Wizard. The default database file path and default log
folder path are set automatically to be the same as those used for
other Exchange data.
Any new mailbox databases you create using the Exchange Management
Console are configured to use the mailbox provisioning load balancer by
default. When you create mailbox databases using the Exchange
Management Shell, you can use the –IsExcludedFromProvisioning parameter
to specify that the database should not be considered by the mailbox
provisioning load balancer. Excluding a database from provisioning
means no new mailboxes are automatically added to this database. Rather
than excluding a database from provisioning, you can use the
–IsSuspendedFromProvisioning parameter to specify that a database be
temporarily not considered by the mailbox provisioning load balancer.
To create a mailbox database, complete the following steps:
-
In the Exchange Management Console, expand the Organization Configuration node, and then select the related Mailbox node. -
In the details pane, the Database Management tab is selected by
default. You should see a list of active databases that are available
in the Exchange organization. -
In the left pane, right-click the Mailbox node, and then select New
Mailbox Database from the shortcut menu. You should now see the New
Mailbox Database Wizard, shown in Figure 1.
-
In the Mailbox Database Name text box, type a name for the mailbox database. -
Click Browse to the right of the Server Name text box. Select the
Mailbox server that will host the mailbox database, and then click OK.
(See Figure 2.) Only Mailbox servers in the Active Directory forest to which you are connected are available. Click Next. -
On the Set Paths page, shown in Figure 3,
the database file path and log folder path are set to the default
location for Exchange data on the selected server. If you don't want to
use the default locations, enter the paths you want to use for the
database file and the related logs in the text boxes provided. Select
the Mount This Database check box if you want to mount this database.
Mounting a database puts it online, making it available for use. Click
Next.
Note
The wizard creates any required folders on the server if they do not exist.
-
Click New to create the mailbox database, and then click Finish. On
the Completion page, the Summary states whether the operation was
successful. If an error occurred, you need to take the appropriate
corrective action. Otherwise, you can now modify the properties of the
mailbox database as necessary.
In the Exchange Management Shell, you can create mailbox databases using the New-MailboxDatabase cmdlet. Example 1 provides the syntax and usage.
Example 1. New-MailboxDatabase cmdlet syntax and usage
Syntax
New-MailboxDatabase -Name DatabaseName -Server ServerName
[-EdbFilePath DbFilePath] [-LogFolderPath FolderPath] {AddtlParams}
{AddtlParams}
[-DomainController FullyQualifiedName][-IsExcludedFromProvisioning <$true
| $false}] [-IsSuspendedFromProvisioning <$true | $false>]
[-OfflineAddressBook OfflineAddressBook]
[-PublicFolderDatabase DatabaseName]
New-MailboxDatabase -MailboxDatabaseToRecover DatabaseName
-Recovery <$true | $false> -Server ServerName
[-DomainController FullyQualifiedName] [-EdbFilePath DbFilePath]
[-LogFolderPath FolderPath]
Usage
New-MailboxDatabase -Server "CorpServer88" -Name "Accounting Database"
-EdbFilePath "C:\Databases\Accounting\AccountingMail.edb"
-LogFolderPath "D:\DatabaseLogs\Accounting"
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