Microsoft recognizes the need for people to determine how
much free space is available in an Exchange Server database. In Exchange Server
5.5 and later, the amount of free space that is available in a database is
displayed in an event that is logged in the event log after an online
defragmentation of the database is performed. Note that the online
defragmentation is performed automatically during normal information store
maintenance. In addition, note that the event is logged in the event log even
if the associated logging level is set to
None.
Events that are similar to the following events are
logged in the event log
Event: 1221
Source: MSExchangeIS Private
Type: Information
Category: General
Description: The database has nnn megabytes of free space after online defragmentation has terminated.
Event: 1221
Source: MSExchangeIS Public
Type: Information
Category: General
Description: The database has nnn megabytes of free space after online defragmentation has terminated.
where
nnn is the amount of free space
that is available in megabytes.
NOTE: In Exchange 2000, the event ID 1221 message description contains
the following text
The database "storage_group\mailbox_store (server_name)" has nnn megabytes of free space after online defragmentation has terminated.
where
storage_group is the name of the
storage group,
mailbox_store is the name of the
mailbox store,
server_name is the name of the
Exchange 2000 Server computer, and
nnn is the amount
of free space that is available in megabytes.
NOTE: To determine the total space, make sure that you take the total
of the event ID 1221 messages between the event ID 179 (beginning of full pass
of OLD) and either event ID 180 (completed full pass of OLD) or 182 (completed
resumed pass of OLD).
If one of the preceding events indicates that
significant free space is available in the database and you recently performed
an operation that may have caused a large number of objects to be removed from
the database, you may want to perform an offline defragmentation. The following
are some examples of operations that may cause a large number of objects to be
removed from the database:
- Moving a large number of mailboxes
to
another mailbox store.
- Changing the retention time or disk quota for deleted
items.
- Receiving a large number of messages (for example, junk
e-mail), and then deleting the messages.
To perform an offline defragmentation of the database, perform
the following steps.
NOTE: Microsoft recommends that you only perform an offline
defragmentation of the database when you have performed an operation that
caused a large number of objects to be removed from the database. Performing an
offline defragmentation under any other circumstances may actually hurt
database performance.
- Stop the information store service:
- In Control Panel, double-click Services.
- Click the Microsoft Exchange Information Store service, and then click Stop. If a dialog box is displayed that states that additional
services will be stopped, note the services that will be stopped, and then
click OK.
- Defragment the public and private information stores by
using one of the following methods, as applicable:
- Start the information store service:
- In Control Panel, double-click Services.
- Click the Microsoft Exchange Information Store service, and then click Start.
- Start any additional services that were stopped when you
performed step 1.
- Perform a full online backup of the information store
databases.
This feature is included in the latest Microsoft
Exchange Server version 5.5 U.S. service pack. For information on obtaining the
service pack, query on the following word in the Microsoft Knowledge Base
(without the spaces):
S E R V P A C K
For more information, click the following article numbers to view the articles in the Microsoft Knowledge Base:
178931
Database size after offline defrag not same as total K
181824 Exchange database engine does not detect removed page in b-tree split operation
185271 Orphaned LV errors running ESEUTIL Consistency Checker
183888 Free
disk space requirements for Eseutil.exe