In my recent posts I discussed the fundamentals of Exchange Server 2007 high availability and how to use Local Continuous Replication.  In this post I will demonstrate one of the two Exchange Server 2007 clustering methods, Single Copy Clusters.

What are Single Copy Clusters?

Single Copy Clusters (SCC) for Exchange Server 2007 is basically the same as clustering in previous versions of Exchange Server.  Two cluster server nodes connect to shared resources in an active/passive configuration.  The two servers appear to other computers to be a single system, and when one server node fails the clustered resources are able to fail over to the other node and continue operation.

SCC provides high availability for the Mailbox Server by protecting it from the failure of either cluster server node.  Typically the cluster will also consist of redundant networking (e.g. teamed network interfaces, multiple switches) and storage components (e.g. a SAN that is in itself a highly available system through redundant components).  The servers are also usually located in high quality data centers with redundant power and cooling.

SCC is available in the Enterprise edition of Exchange Server 2007.  Because it uses an underlying Windows Server failover cluster, the servers that form part of the cluster must also run the Enterprise edition of Windows Server (either 2003 or 2008).

Unlike LCR an SCC cluster offers high availability benefits but no performance benefits.  Because there is a single copy of each mailbox database within the cluster there is no opportunity to use a passive copy for backup operations.

How to Install a Single Copy Cluster

In this example two Windows Server 2003 Enterprise edition servers have been configured with the basic requirements of a failover cluster:

• A public network interface for normal network operations
• A private network interface for the cluster “heartbeat”
• Shared disk storage for the database, log files, and cluster quorum disk

Once the failover cluster has been configured we can install Exchange Server 2007 on the first node.  Run setup as normal, and when selecting the roles to install choose “Active Clustered Mailbox Role” as the server role.  You will notice that a clustered mailbox server cannot co-exist with any other server role. Continue reading Exchange Server 2007 High Availability Part 3 – Single Copy Clusters

In my last post I explained the basic concepts of Exchange Server 2007 high availability.  In this post I will demonstrate one of the Exchange Server 2007 HA features that is called Local Continuous Replication.

What is Local Continuous Replication?

Local Continuous Replication (LCR) uses asynchronous log shipping technology to maintain a copy of a mailbox database on another locally connected disk volume.

For example, the mailbox database and transaction logs may reside on fast, expensive SAN disks, but the LCR copy is kept on slower, cheaper SATA disks.

LCR provides high availability for the Mailbox Server by protecting it from a storage failure.  If the SAN disks failed or became disconnected for some reason the server could continue serving end users via the replica database, possibly at a degraded performance level if the slower disks were not able to handle the required I/O load.

Because LCR is available in both Standard and Enterprise editions of Exchange Server 2007 it is a fairly easy way to achieve some high availability for the server. Continue reading Exchange Server 2007 High Availability Part 2 – Local Continuous Replication

Microsoft Exchange Server 2007 has several different Mailbox Server high availability features included with the product.  Each of the features is similar to the others in some ways but also very different.

In this post I will explain each of the high availability features and which types of scenarios they are suitable for.

What is High Availability?

High availability is a term used to describe the avoidance of unplanned downtime for a computer system through the implementation of hardware and/or software solutions.  Generally speaking a high availability solution will involve the elimination of and single points of failure in the system, often by duplicating or replicating components of the system so that if one fails the other is able to continue performing the role.

An example of downtime would be an email server that has suffered a hard disk crash and is unavailable to users who are then unable to send or receive email.  An example of a high availability solution in this case would be the use of a RAID volume to protect from single disk failures. Continue reading Exchange Server 2007 High Availability Part 1 – HA Fundamentals

Back in Part 2 of this series I demonstrated how to backup the Exchange Server 2007 Mailbox Server role, and then how to use that backup to restore an entire mailbox database in the event of a disaster.  In this part of the series I will demonstrate how to use that same backup to recover individual mailbox items.

Mailbox Item Recovery for Exchange Server 2007

The backup utility that is provided with Windows Server 2003 is capable of backing up and restoring entire mailbox databases for Exchange Server 2007.  However it is not natively capable of restoring an individual mailbox item (such as a single email) should the need arise.

Some third party Exchange backup products do provide this functionality however this comes at a cost.  Fortunately all they are doing is providing a simple interface for a built-in feature of Exchange Server 2007 to perform the restore.

For businesses on a budget or anyone who simply chooses to use the built-in backup utility for backing up their Exchange servers you can still recover individual items thanks to Recovery Storage Groups.

What is a Recovery Storage Group?

A Recovery Storage Group is an Exchange Server 2007 feature that allows the administrator to create an “invisible” storage group that can be used to restore a mailbox database and extract data from it without affecting the production database that is being accessed by end users.

The Recovery Storage Group is only used for restore and recovery operations.  It is never connected to by an end user using Outlook or other mail protocols, and the mailboxes contained within it are not associated with any Active Directory user accounts.

Restoring Mailbox Items using the Recovery Storage Group

In this example the user “John Smith” has deleted an email from the inbox that was received last week.  The Mailbox server is backed up every night and so the email administrator knows that the item is likely contained within one of the previous nights’ backups. Continue reading Exchange Server 2007 Backup and Recovery Part 5 – Recovering Individual Mailbox Items

In Part 1 of this series I discussed backup and recovery for each of the Exchange Server 2007 server roles and associated systems such as Active Directory.  In Part 2 I then described the process of backing up and recovering a Mailbox Server from the loss of a mailbox database.  In this part of the series I will demonstrate backup and recovery of the Hub Transport Server and Edge Transport Server roles.

Backing up Transport Servers

Unlike Mailbox Servers, the Hub Transport and Edge Transport roles do not require any special Exchange-aware backup software.  All of the necessary data for recovering a Transport server is contained within:

• Active Directory (for Hub Transport servers, but not Edge Transport servers)
• The Active Directory Application Mode (ADAM) database (for Edge Transport servers)
• The server’s file system
• The server’s System State

Hub Transport servers can be backed up using the built in Backup utility in Windows Server.  At the very least the backup should include the System State and the C:\Program Files\Microsoft\Exchange Server\TransportRoles location of the file system (and all sub directories).

Edge Transport servers are backed up in the same way as Hub Transport servers except for the Exchange Server configuration.  Because this is stored in ADAM it must first be cloned using the Export-EdgeConfig.ps1 script located in C:\Program Files\Microsoft\Exchange Server\Scripts.  Execute the script with the name of the file you wish to export to. Note this is a single command run on one line in the Exchange Management Shell.

export-edgeconfig.ps1 c:\edgeconfig.xml
 -key "abcdefghijklmnop"

It is recommended to either include this config file in your Edge Transport backups or use a path that is a shared folder on a remote server.

Recovering Hub Transport Servers

In this scenario the EXCHHUB server has been lost due to hardware failure.  Spare server hardware has been used to reinstall Windows Server 2003 along with the Exchange Server 2007 pre-requisites.  The newly built server has the same name and IP address of EXCHHUB.  Now we can begin the recovery of the Hub Transport server.
Continue reading Exchange Server 2007 Backup and Recovery Part 3 – Transport Servers

In Part 1 of this series I explored what needs to be backed up for each of the different Exchange Server 2007 server roles.  In this post I will demonstrate a Mailbox Server failure and the recovery of the mailbox database from backup.

Backing up the Databases

The first thing we’ll need is a backup of the databases on the Mailbox Server.  For this demonstration I am using the built in NTBackup program for Windows Server 2003 to back up both of the storage groups for the server.

Mailbox Server Failure

The next step is to cause a server failure.  In the real world a potential point of failure for Mailbox Servers is the storage.  Typically databases will be located on SAN volumes, and a storage failure will cause the database to go offline.  To simulate this I simply remove the database file from its path on the test server.

Restoring the Database

Before beginning the database restore operation we must first prepare the database for recovery.  Continue reading Exchange Server 2007 Backup and Recovery Part 2 – Mailbox Servers

One of the least exciting yet most important parts of an Exchange administrator’s job is making sure that the Exchange Server environment is properly backed up.  Throughout my career I’ve spent many long nights with customers who have suffered a failure of an Exchange server and discovered that their backups are unreliable or even non-existent.  In this series I will discuss Exchange Server 2007 backup and recovery and demonstrate some actual disaster recovery scenarios that I have encountered on the job.

What to Back Up on Exchange Server 2007

To understand what to back up in an Exchange Server 2007 environment you must first consider the server roles that you have deployed.  In the most basic Exchange Server 2007 deployment the Client Access, Hub Transport, and Mailbox server roles are installed.  In more complex environments more than one of each of those roles might be deployed, the Mailbox server might also be clustered for high availability, and other roles such as Edge Transport and Unified Messaging might also be in use.

In addition to the Exchange server roles there are also considerations such as the Active Directory (a pre-requisite of any Exchange environment), client data such as PST files or POP3 mailboxes, and any server-based anti-spam system that is deployed.

All Exchange Servers

Generally speaking all Exchange servers in an organisation should have their local file systems and System State data backed up.  However because Exchange Server 2007 stores much of its configuration in Active Directory you can recover some server roles without needing to have backed up any data at all.

Continue reading Exchange Server 2007 Backup and Recovery Part 1 – What Needs to be Backed Up?

In part 1 of this series I introduced Exchange Server 2007 Resource Mailboxes and demonstrated how to create Room Mailboxes.  In part 2 of this series I went on to demonstrate how to create Equipment Mailboxes.  Now in part 3 of this series I’ll demonstrate creating custom resource properties for Resource Mailboxes.

What are Custom Resource Properties?

Custom resource properties are additional attributes that can be assigned to Room and Equipment mailboxes to indicate which features are available for those resources.

For example, in an organisation that has several meeting rooms with different features, custom resource properties can be used to show which room has teleconferencing equipment, which one has a whiteboard, which one has tea and coffee facilities, etc.

Similarly for Equipment mailboxes custom resource properties can indicate features such as which vehicles have a GPS installed, or what kind of vehicle (such as truck, van, car) it is. Continue reading Exchange Server 2007 Resource Mailboxes Part 3 – Custom Resource Properties