In today's environment communication and information are everything, and often the heart of this is our email systems. Our dependency on Microsoft Exchange has grown to the point that many of our users have higher expectations than can be delivered, expecting email to always be there like the switch on the wall giving you light, and the phone allowing you to call out.these utility services are often taken for granted.

Our customers have been looking to recover their Exchange 2003 environment within minutes rather than hours
So it's not surprising when customers ask Servo for a solution that will enable them to provide rapid recovery of the Exchange environment without the delays resulting from tape recovery. Our customers have been looking to recover their Exchange 2003 environment within minutes, rather than hours, enabling them to maintaining the highest level of availability.

As a result of these requests I started looking at Microsoft Windows Volume Shadow Services (VSS) - a service that is provided free of charge with Server 2003 - looking at Snapshot capabilities within the operating system. It soon became clear that the operating system provided the framework to enable Exchange Snapshots by placing the Exchange Information Store in a frozen state, but it didn't provide the writer (the mechanism to create the snapshot). For this I would need additional software which would allow me to take point in time copies and place them on disk, or on tape.

The technology explained
Volume Shadow Copy service co-ordinates the backup requests from a Volume Shadow Copy-compliant backup application with Exchange 2003. Veritas, Computer Associates and HP all have compliant backup software however not all vendors have done this yet, for example IBM is yet to release a Tivoli Storage Manager VSS complaint agent, so you do need to check with your existing backup vendor.

Acting as the framework, Volume Shadow Copy services enables individual applications to prepare their data to be captured. In the case of Exchange 2003 as the service provider, once a request is received it flushes pending transactions from the logs before allowing the point-in-time copy to be made. This ensures when a shadow copy (or snapshot) is taken it is a consistent clean copy of the Exchange databases and log files.

The process takes place as follows

1	The backup requestor signals its intent to back up a particular data set.
2	The Volume Shadow Copy service notifies Exchange, which flushes the transaction logs and freezes write I/O requests for the selected storage groups.
3	Once this process is complete, Exchange notifies back that the copy may proceed.
4	The requestor proceeds with the backup, after which the Volume Shadow Copy service notifies Exchange that normal operations may resume.

This approach helps guarantee that all copies of the Exchange data are clean and consistent but it doesn't help speed up the Exchange recovery. In essence it provides me with an enhanced on-line agent that doesn't need the Exchange server to be downed, but it doesn't give me data recovery in minutes.

Achieving high speed recovery So we can use Volume Shadow Copy to freeze the Exchange Information Store and flush out the transaction logs, but how can you get your environment back in minutes? Assuming that Exchange Information Store is being clustered to provide application and hardware failover, Veritas Storage Foundations for Windows in conjunction with HP storage can provide data protection for your information store that enables the recovery within minutes.

To speed up recovery of a corrupted Exchange database you could consider backing up to disk first instead of tape, greatly improving the recovery time. This would meet service level agreements of 4 hours or more. However for immediate recovery of the Exchange Information store more organisations are looking at hardware and software snapshot technology.

Veritas Storage Foundation works on the principle of mirroring or duplicating the production volume on either the same storage enclosures or on an alternative server. Once the mirror is completed it remains in sync until a Snap Shot command breaks the connection, providing a full and complete copy of the original disk.

This volume can then have a drive letter assigned and accessed directly or using a Veritas provided utility have the Exchange database integrity checked off-line. The snap shot can be used for backups or can be mounted within a Storage Recovery Group, allowing individual mailboxes to be recovered from the snap shot.

The above illustration shows two mirrors of the Exchange production volume. Mirror 2 in this example is broken to provide a fully functioning point in time copy of the original volume. By managing this snapshot technology you are able to fully recover database volumes within minutes. During the restoration process for example, the server file system could be redirected to the snapshot volumes. Because no data transfer is required from tape or disk backup solution the Exchange databases can be mounted immediately, providing close to instant recovery.

	Quick Recovery for Microsoft Exchange 2003 So, if you need to recover your Exchange 2003 environment within minutes whilst maintaining the highest levels of availability then using VERITAS Storage Foundation for Windows coupled with Microsoft Volume Shadow Copy will provide an extremely rapid recovery of Microsoft Exchange 2003 without the need to shut down the Exchange services. It is an affordable way to maximize Exchange 2003 availability, whilst utilising the Microsoft VSS framework.

Rapid recovery for this solution is achieved by creating persistent snapshots of volumes, which are used to replace the current production volumes if a corruption or database loss occurs. This process allows for a first line of defence that is significantly faster than restoration from standard backup, typically from tape.

For more information
HP Storage Solutions for Microsoft Exchange Server 2003
http://www.hp.com/solutions/microsoft/exchange/storage

Technical Review Guide, datasheet, and other materials for Storage Foundation for Windows
http://www.veritas.com/Products/www?c=product&refId=31

Microsoft Exchange Server
http://www.microsoft.com/exchange