Exchange 2007 Creates New Possibilities for Data Protection

The next release of Microsoft Exchange Server will be called Exchange 2007 and is due for release in early 2007.  Last month at Microsoft TechEd in Boston, many Exchange experts were on hand to share information about this new release.  Exchange 2007 includes many new features and many of these changes impact Exchange data protection.  Increased Exchange storage capacity and new replication tools create new possibilities for protecting Exchange Server from data loss.

It is interesting to note that the number of Storage Groups and Mailbox Stores is the same.  The message here is that Microsoft recommends you keep the ratio of Stores and Storage Groups 1:1.  According to Microsoft experts, this will improve overall performance and improve recoverability by having one set of dedicated transaction log files per Store.  If your current Mailbox Stores are growing too large, you will be able to split your users into more Stores with Exchange 2007 and keep recovery time acceptable.

According to the Microsoft experts in Boston, Exchange 2007 can now support mailboxes that are 1 GB to 2 GB in size, and a single Exchange Server can support 3,000 to 4,000 total mailboxes.  Sitting in the audience at TechEd, it seemed that everyone was hoping that Exchange would support more mailboxes, say in the 10,000 mailbox range, but compared to Exchange 2003 this is still quite an improvement.  Moving to Exchange 2007 will require new investment in server hardware and memory, but being able to support more users per server will help offset some of this cost.

Also new with Exchange 2007 are two replication features.  They are called Local continuous replication (LCR) and Cluster continuous replication (CCR).  As their names imply, LCR works locally to protect Exchange databases and CCR works in an Exchange GeoCluster.  What is very interesting about LCR and CCR is that they both introduce log shipping to Exchange for the first time.  If you are familiar with Microsoft SQL Database, they you probably are already familiar with log shipping.  Log shipping is a mature and non-invasive technology for protecting database information using the transaction log files.

Let’s first take a look at LCR.  LCR is configured per Storage Group and one database is the maximum per Storage Group. When enabled, the LCR volume is seeded automatically with an ESE Full backup and it is updated continuously with new transaction log files. Once copied to the LCR volume, the log files are applied immediately to the replicated database. To help make this practical, transaction log files are now 1MB in size, vs. 5MB for Exchange 2003.  LCR provides fast recovery of an entire Exchange database in the event of a disk error. In fact, all it takes to recover a database is to move the mount point of the database to the LCR volume using your disk management tools.  Having LCR enabled reduces the reliance on tape backup and Microsoft suggests that you can change your backup schedule to a weekly full and daily incremental type schedule.

CCR operates using a three node (minimum) Exchange GeoCluster.  Two nodes (active/passive configuration only) contain the matching mailbox servers and the third node (referred to as the voter) is used to avoid an occurrence of network partition within the cluster, also know as split brain syndrome.  When enabled, the CCR volume is seeded automatically with an ESE Full backup and it is updated continuously with new transaction log files. Once copied to the CCR volume, the log files are applied immediately to the replicated database.  CCR replaces the need to use costly array-based replication technologies to manage synchronous Exchange data sets in a GeoCluster.  CCR still requires LAN performance between nodes which is costly.

The good news of Exchange 2007 is the expanded storage capacity due to the new 64-bit environment and the new replication tools using log shipping technology that provide improved recovery performance and new disaster recovery options.  It will be interesting to share after Exchange 2007 is in production, if indeed Exchange recovery is improved.  My hunch is that it will and we will all look back and wonder how we ever managed without tools like LCR and CCR and with so few Mailbox Stores.

Bob Spurzem

bspurzem@mimosasystems.com

Sr. Product Marketing Manager

Mimosa Systems, Inc.