Recently, we tried to restore Exchange 2007 database on SCC cluster. Unfortunately, we got below error messages:

Failed to dismount database in First Storage Group on mailserver.mailclu.contoso.com (ID:30144 Detailed information: Incorrect parameter (0x80070057))

However, we performed the same steps on a non-clustered Exchange 2007 server, and we success.

We searched a lot information, and read DPM 2007 online document carefully, and we didn't fine any valuable information on this point.

Finally, we investigated DCOM component on cluster. As you know, we now don't install comclust on Exchange 2007 cluster. However, operations on cluster most often depends on DCOM component. So, we tried to add comclust on the cluster. But, we still got the same error message when we try to restore database on the cluster exchange 2007.

We also invest many time on permission for DPM. As you know, if some utilities want to perform operations on exchange database, it needs necessary permission the the object. So, we checked service account for DPM agent on Exchange 2007 cluster: Local System. Definitely, it has no any permissions on exchange objects. A thing want to know is, how we add necessary permission for this, because there is no any configuration interface for DPM agents.

Thanks to one of my collogues, he found that there is a DOM component, named ExchangeCmdletsWrapper, we can specified an account here which has the necessary permission for performing exchange objects. For adding this account, follow up below steps on both active and passive cluster nodes:

-Run dcomcnfg

-Go to Component services->My Computer->Dcom config->ExchangeCmdletsWrapper

- Right click on ExchangeCmdletsWrapper, select properties,

- go to identity tab

- Select "this user"

- Give credentials for the account which has Exchange admin privilage

- Select apply

Then, Move Exchange Group to another node for making sure the specified account taking effective.

We got success after making this change.

Note: Before you run mentioned steps, you must enable DCOM on cluster: How to configure Microsoft Distributed Transaction Coordinator on a Windows Server 2003 cluster

Good Luck!