Perform Exchange Server Recovery when afflicted by Error 9518

By | March 16, 2012

Microsoft Exchange Server Information Store is the comprehensive element that every Exchange administrator needs to master for efficient management of the server. Exchange Information Store contains the Exchange Storage Group and Public Folder Stores. For MS Exchange 2000 and 2003, the Storage Group will comprise of a user mailbox store and public folder that contain EDB and STM files. A .stm file is associated with each .edb file.

At imes when the user mailbox store or public folder is mounted on the Exchange Server, the following error message is encountered:

“Event Type: Error

Event Source: MSExchangeIS

Event Category: General

Event ID: 9518

Date: date

Time: time

User: N/A


Description: Error 0xfffffc01 starting Storage Group”

Cause of the error:

There are two conditions that result in the occurence of Exchange Error 9518. The first is that an incorrect drive letter is set for Exchange database files or log files. The second is that the antivirus software can restrict access to the drive containing the Exchange database or transaction log files. Transaction logs are files that are cardinal for the working of Exchange Server. If any of the above conditions is true, the Exchange database will not mount and all the user mailbox data such as emails, attachments, contacts, appointments and notes will become inaccessible.


If the problem is caused by the anti-virus software, try to disable it and then mount the mailbox store. If the problem is due to transaction log files, follow these steps to perform Exchange Repair:

  1. Start Exchange System Manager and expand Administrative Groups.
  2. Choose and expand the Administrative Group that is experiencing the aforementioned error.
  3. Expand Servers, choose the server that is experiencing the problem and expand it.
  4. Right click on the storage group that fails to mount, click Properties.
  5. Examine the path in Transaction log location box in the General tab and the path in System path location box.
  6. For incorrect paths, click Browse to locate the actual folders containing log files or database files. Click Ok.

Once the database file or log file path has been verified for each Storage Group, the path for each store in the Storage Group also needs to be verified through these steps:

  1. Expand a storage group, right click StoreName (ServerName)-> Properties.
  2. Click database tab, verify the path that appears in Exchange database box and Exchange streaming database box.
  3. For incorrect paths, click Browse to locate te actual folders and click Ok.

Once the aforestated steps are carried out for each storage group, the mailbox store should mount successfully. If the problem remains unsolved, then it is a critical case of Exchange Information Store corruption that can only be resolved through the use of third party EDB Repair tools. These tools can recover cardinal EDB and STM file data into Outlook importable PST files for one or more user mailboxes.

About the Guest Post Author: Cauvery Varma is a technology specialist, working with Stellar Information Systems Limited. She is a passionate blogger who writes helpful articles about Exchange EDB Repair tools.