Monday, August 16, 2010

Commvault Exchange 2007 Backup Agent Considerations

I was testing backups of Exchange with Commvault 8 a while back and realized there was a little more to it than just running the standard install of the agent. My Commserve/Media agent was running Windows 2008 64bit as well as my Exchange 2007 VM. I installed the Commvault Exchange DB and the required Windows File System agent with ease and was backing up and recovering within minutes. I was ready to proceed with the installation of the Mailbox and Public Folder agents when I remembered, “These agents are 32 bit, so I need to run the server in mixed mode! Again, no big deal, I set the registry setting (http://documentation.commvault.
com/commvault/release_8_0_0/books_online_1/english_us/search/search.htm) and “Voila!”, the 32 bit binaries showed up. I realized at this point that these 32 bit agents would require the 32 bit Windows File System Agent as well. That’s 2 file system agent licenses required for a single VM. I thought, “What about Exchange Clusters?” Sifting through Commvault’s documentation, I found a diagram describing Exchange Agents required in an x64 cluster:

Hmmm….that’s a total of 6 Windows file system agents for a single two-node Clustered Exchange instance!

Running the slower 32-bit MAPI-based Exchange backups may be sufficient if you have a large enough backup window. If not, using the 64-bit Exchange database backups in conjunction with the Offline Recovery Tool for Exchange (for individual mailbox recoveries) would be the way to go. For larger backup environments, Commvault’s capacity based license would make this a moot point.


Rowan pointed out another way to utilize a combination of Exchange Database and Mailbox agents without needing to install both 32 and 64-bit file system agents on the Exchange 2007 server. The 32-bit mailbox and file system agent can be installed separately on a 32-bit off-host proxy media agent. This not only eliminates the need to install the agents in mixed-mode, but also takes the backup load off of the Exchange 2007 server. Thanks, Rowan!



  1. Genny, did you know that if you install the 32-bit mailbox and file system agent to a virtual machine (potentially also 32-bit) you could cut that down to just 3 file system agents?

    It certainly avoids the mess that is multiple instances on one host and the need to create CNAME's etc. Also, by adding more subclients to the agent backupset, you can have multiple streams "attacking" the Exchange mailbox stores at the same time to increase backup throughput. Once combined with an ongoing incremental and synthetic full backup schedule, you probably won't have any need to run a true full backup ever again.

  2. Rowan,
    You’re right in respects to the 32 bit file system and mailbox agents, but a 32 bit Exchange DB agent for Exchange 2007 (to backup the mail stores) is not available. Microsoft, for the most part, does not support 32 bit installations of Exchange 2007 in production environments. There are some exceptions, but those exceptions relate to extending the schema of AD or utilization of the Exchange management tools, none of those being core functionalities of a typical Exchange server.

  3. Yes, it's certainly true that there is no 32-bit agent for Exchange 2007 database backups, CommVault provide the 64-bit agent for this reason.

    My comments were aimed at helping reduce the complexity of setup in the instance that a customer does have virtualization technology in play. Even if they don't, the mailbox agent for MAPI brick level backups can be installed to a CommVault MediaAgent that is not the Exchange server.

    It goes without saying though that it would be so much simpler if Microsoft provided a 64-bit version of the MAPI protocol or exposed mailboxes via WebDAV. :)

  4. Rowan, great point re: installation of the agents on an off-host proxy! So many ways to skin the cat when it comes to Commvault. :D I've updated my blog to include your suggestion.

  5. For backup and recovery MS Exchange data you can use Exchange mailbox recovery. It owns all necessary capabilities such as working under all Windows OS and with all software configurations of your PC. The program doesn't modify source data of edb during recovering.