Cloud Definitions
Today everybody is talking about clouds: what they are; how to use them and if using them is suitable for their organization. In general “cloud computing” can be defined as server based computing in virtual environments in decentralized datacenters. This means that these servers are accessible via WANs and do not exist in the local network.
In general there are three kinds of cloud technologies:
- Public Clouds
- Private Clouds
- Hybrid Clouds
Public Clouds are IT environments that are hosted at big providers (like Microsoft, Google or Amazon). These data centers are spread all over the world with high availability functionality. They are often called “Software as a Service” solutions, because the servers are not dedicated for your company because all data of all customers is hosted by these servers in parallel.
Private Clouds are IT environments that are hosted by your organization but the underlying technology is the same as in Public Cloud environments. This means you are prepared for the cloud but are running your own cloud, either in your data center or in a collocated data center of a big provider.
Hybrid Clouds are a mixture of public and private cloud designs based on the technology needs of your company.
This article will discuss how to migrate a dedicated, non-virtualized Exchange Server 2010 SP1 environment into a Private Cloud based collocated data center without disruption of mail transfer for the users.
Requirements
To easily prepare and run the migration, you need to fulfill the following requirements:
- All Exchange Servers are running Exchange Server 2010 Service Pack 1 and same patch level of Windows and Exchange
- A high available Exchange organization with DAG (Database Availability Group) and dedicated Exchange Servers running the Hub Transport and Client Access Role.
- A “high speed” connection to the internet (100 Mbit or more are quite good, because the more performance you will have, the quicker your migration will be finished)
- Complete routable network
- Local Domain Controllers (with Global Catalog Role) available in the collocated data center
- Clients are already connecting to Exchange using the “Outlook over the Internet” feature
Preparation Tasks
- Installation of 2 Windows Server 2008 R2 Standard Edition (for running Hub Transport and Client Access Role)
- Installation of 2 Windows Server 2008 R2 Enterprise Edition (for running Mailbox Server Roles in a DAG)
Phase 1 – Co-Existence
- Installation of Exchange Server 2010 SP1 on the two Standard Edition Servers with Hub Transport and Client Access Role enabled
- Installation of Antivirus and Backup Agents on these new servers
- Copy the configuration of Hub Transport and Client Access Roles to these new servers
- Configure the Client Access Servers as “CAS Array” for high availability
- Installation of Exchange Server 2010 Sp1 on the two Enterprise Edition Servers with Mailbox Role enabled
- Installation of Antivirus and Backup Agents on these new servers
- Configure these two servers as member of the existing Database Availability Group(s)
- Wait for replication for all databases has completed on the new servers
- Enable network access for all clients to the new Client Access Servers
Phase 2 – Demotion of local Exchange Servers with Hub Transport and Client Access Roles
- Disable SMTP connectors on all local Exchange Hub Transport Servers
- Change remote proxy configuration to route Outlook Web App and Exchange Server Sync to the new Client Access Servers
- Uninstall Exchange Server from both local Client Access and Hub Transport Servers
- Unjoin these Servers from your domain
- Shut them down completely
- Check if all clients can work properly
Phase 3 – Demotion of local Exchange Servers with Mailbox Roles
- Unjoin both local Exchange Mailbox Servers from your DAG configuration
- Uninstall Exchange Server from these servers
- Unjoin them from your domain
- Shut them down completely
- Check if all clients an work properly
Phase 4 – Finalize the Migration
After having finished the migration to the “private cloud”, you should now make sure that:
- Documentation of the new server structure
- Enable Monitoring for your new servers to early find out where possible problems may occur
- Provide QoS (quality of service) on your WAN lines to make sure that you can provide enough performance to your clients when the connect to their Exchange Servers in the collocated network
Unified Communication Role
Because the Unified Communication Role of Exchange Server 2010 SP1 is still not approved for high availability and virtualization, you need to manually transfer this role to your collocated data center with a period of unavailability of this service.
The following steps are usually needed for this transfer:
- Power off your server hosting the Unified Communication Role
- Ship this server to your collocated network
- Power on your server in the collocated network
- Change the IP configuration of this server
- Restart it and enable service availability
General Information
If you do not have “high availability” in your environment today, it might be interesting to implement a single server database availability group (DAG), too. This will make your migration into the cloud much easier because then you could create a temporary DAG solution to easily migrate your mailboxes to the cloud without interfering users.
Conclusion
As you hopefully would have recognized a migration to a private cloud data center with Exchange Server 2010 Service Pack 1 is quite easy. It is a step forward and proved solution. If you still have any questions, please do not hesitate to contact me.
