Users of Microsoft Exchange 2000 Server and Exchange Server 2003 sometimes encounter situations where they are unable to mount their mailbox information stores. The information stores are the most frequently affected components of Exchange Server and when they are corrupted then mounting is not possible.

The information store consists of four database files: Priv1.edb, Priv1.stm, Pub1.edb and Pub1.stm. The Priv1.edb file contains messages that are in-process and also stores non-SMTP messages. The Priv1.stm database file contains in-process and stored SMTP mail messages. The Pub1.edb database file has non-SMTP formatted data in the public folder store and the Pub1.stm database file is the public folder store for SMTP formatted data.

If any of the files in the stores are corrupted and you go into the System Manager and try to mount then you’ll probably see the following error message:

The database files in this store are corrupted.
ID no : c104173b
Exchange System Manager

This is possible after installing some updates or after an unexpected shutdown.

You’ve probably thought about trying a reboot but that will not help  in this case because of a corrupted information store. A symptom of the problem you might find is that when users log into their exchange mailbox they will get an error message about the Exchange Server being down for maintenance. 

The error message that the user will see is:

The MAPI call ‘OpenMsgStore’ failed with the following error:
The Microsoft Exchange Server computer is not available.  Either there are network problems or the Microsoft Exchange Server computer is down for maintenance.
The MAPI provider failed.
Microsoft Exchange Server Information Store
ID no: 8004011d-0526-00000000

And if you try to reboot or mount the folder then you’ll see something like:

Information Store (1780) Database recovery/restore failed with unexpected error -1018.
Information Store (1780) The database engine stopped.
Error Read verification error starting Storage Group /DC=…/CN=CONFIGURATION/CN=SERVICES/CN=MICROSOFT EXCHANGE/CN=…/CN=ADMINISTRATIVE GROUPS/CN=FIRST ADMINISTRATIVE GROUP/CN=SERVERS/CN=…/CN=INFORMATIONSTORE/CN=FIRST STORAGE GROUP on the Microsoft Exchange Information Store.

You can get into a Catch-22 situation (darned if you do and darned if you don’t) if you try some of the ESEUTIL commands. You may see some JET errors. If you try to restore the store(s) you might get errors from the backup software that indicates that the store(s) is/are in use. And if you try to delete it then you get a message back that warns that the users have emails.

Sometimes in the troubleshooting process you are able to fix the most recent error but then another pops up. You fix that one and then another error occurs. My point is that your most recent error message is just another layer. You need to determine the root of the problem to avoid layers of errors that can vacuum up your time in the troubleshooting process.

But with the c1014173b error message it is a strong indication that one or more of your information stores are corrupted. You’ll need to repair them. You can try to do an Exchange Server recovery if you have the log files and a recent backup. Set your database to an active state. This may not be possible if the backup is not complete.

Another possibility is to try Exmerge and export the mailboxes to another working Exchange Server. But you would need another Exchange Server waiting in the wings and ready to go. Or maybe you are working on time constraints which don’t allow for this action.

You can also try to use the Eseutil/p utility but users have reported that corrupted pages get deleted from the database.

There are third party applications which can help in the recovery process. In the UNIX world there are simple tools such as “fsck” for file system checks. But you’ll need a tool that is designed to can scan through these corrupted information stores. There are utilities on the market that can aide in Exchange Server repair. You’ll need to ensure that they are compatible with your versions and have well designed scanning algorithms. Choose an interface that works best for you, one that is easy to use and offers descriptive help for different corruption scenarios.

Loss of data happens but when it does be prepared to step in and apply the tools that help you recover in the least amount of time. So having the tools on hand before a disaster, not after, is the best practice.

More detailed support information can be found in the  Microsoft article, 313184,  to help you restore the Information Store on Exchange. Review the steps in this article: HOW TO: Recover the Information Store on Exchange 2000 in a Single Site.