Exchange
Server 2007, administrators were constantly reminded that to take
advantage of the improvements in high-availability technology, there
should only be one storage group per database. If having several
databases in a storage group complicated high-availability scenarios and
made single-database restores more complex, why bother having them at
all?
Apparently Microsoft agreed: In Exchange Server 2010 the concept of the storage group is no more.
Databases are now
considered to be “global objects” that are no longer tied specifically
to particular mailbox servers. Where administrators used to go to the
Server Configuration \ Mailbox node in the EMC to view and modify
databases, they now must go to the Organization Configuration \ Mailbox
node.
And where Exchange Server 2007 allowed up to 50 databases per server, Exchange Server 2010 now allows 150.
That’s right—150 databases
per server. This does not mean, however, that administrators should run
out and create 150 new databases on each of their servers; rather, the
intention is to enable organizations to take advantage of database
availability groups, or DAGs. With a DAG, organizations can create up to
16 copies of a database and have them replicated across multiple
servers.
Creating a New Database
Creating a new mailbox
database in Exchange Server 2010 is a straightforward process. Below are
the steps to create a new database in the EMC.
1. | Start the Exchange Management Console.
| 2. | In the Console Tree, navigate to Organization Configuration, and select the Mailbox node.
| 3. | In
the action pane, click either New Mailbox Database or New Public Folder
Database, depending on the type you want to create. This launches the
New Database Wizard.
| 4. | Enter
the Mailbox database name. As there are no more storage groups to
differentiate one database from another, each database name must be
unique within the organization. Click the Browse button to select which
server will house the new database and click Next to continue.
| 5. | Enter
the file location’s Database and Log folder paths. Note that the option
to Mount This database is selected by default. If you do not want the
database to mount automatically upon creation, deselect this option.
Click Next to continue.
| 6. | Review the Configuration Summary and, if all is correct, click New to create the database.
| 7. | Review the Completion page and ensure all steps were completed successfully. Click Finish when done.
To create a new database from the EMS, a sample command is shown here:
new-mailboxdatabase -Server 'E2010-1' -Name 'Mailbox Database 2' -EdbFilePath
C:\Program Files\Microsoft\Exchange Server\V14\Mailbox\Mailbox Database 2\Mailbox Database 2.edb'
-LogFolderPath 'C:\Program Files\Microsoft\Exchange Server\V14\Mailbox\Mailbox Database 2'
To mount the newly created database, use
mount-database -Identity 'Mailbox Database 2'
To dismount the database, use
dismount-database -Identity 'Mailbox Database 2'
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Setting Limits on Databases
After you create a
database, you can customize the maximum storage limits and deletion
settings for mailboxes stored on that database. Although some
organizations consider placing limits of any kind on mailboxes to be
draconian, most understand that preventing users from storing unlimited
amounts of archaic data and enforcing the regular automatic purging of
deleted items helps to ensure a healthy and happy messaging system that
benefits the entire organization.
By default, these
settings apply to all user mailboxes stored on that database. However,
specific limits on individual mailboxes can be configured to override
these database-wide settings. This can be useful when you want to set a
limit for all users on a particular database, but you have one user who
needs more (or less) restrictive settings. To configure these options,
perform the following tasks:
1. | Start the Exchange Management Console.
| 2. | In the Console Tree, navigate to the Organization Configuration and select the Mailbox node.
| 3. | In the results pane, select the database you want to configure.
| 4. | In
the action pane, click Properties to open the database properties
sheet. Note: There are two properties options in the action pane. One
for the database, co-located with Dismount Database and Move Database
Path, enables you to configure the properties of the object. The other
is associated with the database copy and offers general information
about the database copy such as the server status, latest available log
time, and other information. For our purposes, we select the former.
Alternatively, you can simply locate the database you want to modify and
double-click it in the results pane.
| 5. | Select the Limits tab.
| 6. | Several limits are available to configure for the database. You can configure any of the following settings on the database:
- Storage Limits— The
storage limits section enables you to configure restrictions on all
mailboxes located within that database. The available storage limits
options are as follows:
- Issue warning at—
1,991,680KB (1,945MB or approximately 1.9GB). This is not a “hard”
limit, but a warning threshold. When this limit has been exceeded, the
user will get a message warning them.
- Prohibit send at—
2,097,152 KB (2,048 MB or 2 GB). This is a “hard” limit. When a mailbox
exceeds this threshold, the user is unable to send mail. This does not
impact the user’s ability to receive mail, ensuring the user does not
miss any messages while scurrying to clean up their mailbox.
- Prohibit send and receive at—
2,411,520 KB (2,355MB or approximately 2.3GB). This is also a “hard”
limit. When the mailbox exceeds this limit, the user can no longer send
or receive messages. Incoming mail destined for this mailbox will be
returned to the sender.
- Warning Message Interval—
By default, storage limit warning messages are sent daily at 1:00 a.m.
This selection can be customized to perform the warning at a different
time of the day, or even to send multiple messages at various times of
the day. Click Customize to change the default setting.
- Deletion Settings—
The deletion settings dictate how deleted items and mailboxes in the
database will be dealt with. The available deletion settings options are
as follows:
- Keep Deleted Items for (Days)— By default, mailbox databases are configured to keep deleted items for 14 days.
Note
There is
often some user confusion as to what messages can be recovered using the
Tools, Recover Deleted Items option in Outlook. There are two types of
deletion: Hard (or physical) deletion and Soft (or logical) deletion.
When users delete an item, it goes to their Deleted Items folder and can
be recovered simply by dragging and dropping it back into their Inbox.
If users go to the Deleted Items folder, and again delete the message,
or if they select Tools, Empty Deleted Items Folder, the item has been
soft deleted and can be recovered using the Tools, Recover Deleted Items
option. This recovery can be accomplished if it is initiated within the
window set in the Keep Deleted Items for (Days) section field. However,
if a user enters the Recover Deleted Items utility and selects to purge
a message, or if the Keep Deleted Items for (Days) period has expired,
the item is hard deleted and cannot be recovered without resorting to
backup/restore methods.
- Keep Deleted Mailboxes for (Days)—
In Exchange Server 2010, as it was in Exchange Server 2007, deleting a
mailbox does not mean that it is permanently purged from the database
immediately. The mailbox is flagged for deletion and can no longer be
accessed by users. After the mailbox retention period controlled by this
setting has been reached, the mailbox is then purged from the system.
This option is extremely useful if a user deletion occurs that is the
result of a mistake and enables the administrator to re-create the user
object and reconnect the deleted mailbox. By default, this setting is
set to 30 days. It can be configured anywhere from 0 (immediate purge
upon deletion) to 24,855 days. It is unlikely you will ever need the
upper limit (equivalent to a little more than 68 years), but this
setting can be adjusted to meet your organization’s needs. Unless disk
space becomes an issue, it is recommended that you do not disable the
deleted mailbox retention feature.
- Don’t permanently delete items until the database has been backed up—
This final setting is not enabled by default. By checking this option,
you instruct Exchange Server to not delete items or mailboxes, even
after the retention period has expired, until the database has been
successfully backed up. By selecting this option, you ensure that you
can recover critical items or mailboxes from backup tape, even after the
purge has been completed.
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