Acronis Recovery for Microsoft Exchange - User Guide - Manual (Page 32)

5.1.4 Server Roles
As a messaging system that is widely used in both large organizations and small
businesses, Microsoft Exchange Server has always been scalable in both directions.
However, new demands on messaging – such as compliance, security, and disaster
recovery – have created new challenges for delivering a messaging system that works
well in small businesses and large enterprises alike.
Microsoft Exchange Server provides a complete messaging system that can run on a
single server – meaning that all Exchange services reside on one server, as with the
Microsoft Small Business Server product. However, there are significant gains in
deployment, management, and security that come from having a flexible, modular
system that can be installed across more than one machine. Customers would typically
customize their Microsoft Exchange Server 2003 installation, creating specific server
roles manually. In Microsoft Exchange Server 2007, roles are predefined and chosen
during installation. The role selected during installation ensures that only the necessary
services and components are installed.
Microsoft Exchange Server has the following server roles:
• Client Access role - similar to the front-end server in earlier versions of
Microsoft Exchange Server, this server proxies Internet client traffic to the
correct mailbox server.
• Mailbox role - this role hosts user mailboxes stored in databases that can
be replicated or clustered.
• Hub Transport role – this role provides internal routing of all messages –
from Edge servers, Unified Messaging (UM) servers, or between two users
on the same mailbox database. The Hub Transport role is also where
messaging policy is enforced for messages moving within and outside the
organization.
• Unified Messaging role – this role enables PBX integration to allow voice
mail and fax messages to be delivered to Exchange mailboxes, and provides
voice dial-in capabilities to Microsoft Exchange Server.
• Edge Transport role - this server resides outside your internal network
and provides on-premise e-mail security, antivirus, and anti-spam services
for Microsoft Exchange Server.
With the exception of the Edge Transport role, multiple roles or all roles can be
installed on a single system. This is because an Exchange server running the Edge
Transport role in a perimeter network (DMZ) is not a member of Active Directory or the
Exchange organization for security reasons. Another role limitation: clustered mailbox
servers can only be configured with the Mailbox server role.
Acronis Recovery for MS Exchange allows backing up of the Mailbox role only. See
section 5.3 for detailed instructions.
5.1.5 Storage Groups and Information Stores
Exchange Server 2007 Enterprise Edition supports up to 50 storage groups and 50
databases per server. You can configure up to five databases per storage group, and
up to a maximum of 50 databases. Now mailbox data can be distributed across more
databases, and mailbox databases can be distributed across more storage groups, than
in earlier versions of Exchange Server. Exchange Server Standard Edition supports up
to five storage groups and five databases per server. Both Enterprise Edition and
Standard Edition have an unlimited database size limit.
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