Migration Manager for Exchange Database Server Requirement Details
Database Server One of the following:
l Microsoft SQL Server 2005
l Microsoft SQL Server 2008
l Microsoft SQL Server 2008 R2
l Microsoft SQL Server 2012
Database Size Requirements
Disk space required to store SQL database produced by Migration Manager for Exchange depends on a type of
migration you plan to perform.
Migration to Microsoft Office 365 or Microsoft Exchange 2013
If you migrate to Microsoft Office 365 or Microsoft Exchange 2013 by means of Migration Agent for Exchange
(MAgE), then to estimate the disk space that SQL database will take during the course of migration, use the
following formula:
SQL database size = [Total number of mailboxes] x [Average number of messages in a
mailbox] x 1024 bytes [Size of information for single message] x 1.05 [Additional 5%
of size to store error messages]
For a sample migration that involves
l 100 mailboxes
l Around 30,000 messages per each mailbox
The resulting database size is calculated as follows:
SQL database size = 100 mailboxes x 30,000 messages x 1024 x 1.05 = 3,225,600,000
bytes ≈ 3GB
TIP: To calculate total number of mailboxes and number of messages within them, use Quest
MessageStats, or refer to the corresponding Microsoft documentation.
IMPORTANT: If you plan to use express edition of Microsoft SQL Server, consider that database size may
eventually exceed the allowed size limit. That limit is 4GB for SQL Server versions prior to 2008 R2 and
10GB for version 2008 R2 or later. For detailed information on differences between SQL Server editions,
refer to the corresponding Microsoft documentation.
Other types of migration
If you are plan to perform any other type of migration supported by Migration Manager for Exchange, such as
migration with legacy agents or native mailbox move, the database size does not exceed 4GB. Therefore any
database servers stated above can be used as Migration Manager for Exchange Database Server including
express editions.