The Exchange database can become corrupted in different ways, for example, if the Exchange server is shut down incorrectly or if the hard disk is defective. Because it may be difficult to correct a corrupted Exchange database, Microsoft recommends that you perform regular backups of the Exchange database. This article describes how to troubleshoot a corrupted Exchange database.
Trying to repair an Exchange database should be a last resort. Often these attempts can lead to irretrievable data loss. The most common causes of corruption occur in the information store. Typically this will involve any one of public or private EDB files. When an Exchange database is corrupted, you may not see any warning signs, or you may experience the following symptoms:
• You may not be able to access the Global Address List.
• The Microsoft Exchange Server Information Store does not start or you cannot stop it.
• Users cannot send or receive emails.
• Event 1018 is logged in the application event log and hardware failures logged in the system log.
• The client computer may appear to stop responding (hang) for a while.
• You may receive a "failure to connect to the Exchange server" message.
When these symptoms occur, shut down all Exchange services, and then restart the server. Databases like the information store may take a while to shut down depending on their size. When you restart the server, all major services automatically start. If a service does not start, you receive a warning message. You can try to restore the database by using the last known good backup before you run any tools. You can also have the hardware vendor examine the hardware. Any repair process should only be completed at the advice of Microsoft Support. In previous years the advice has always been the same, often using ESEUTIL and ISINTEG repair commands. However Microsoft are changing that process, especially where the repair count is greater than zero. Corruption can linger in a repaired database causing instability, hence mailboxes and public folders are moved to new databases before a repair is attempted. Our advice is to contact Microsoft Support before attempting anything yourself. If they are unsuccessful, give us a call!