Information Store in MS Exchange Server database saves all the public folders and mailboxes. These Information Store components further include two files – priv.edb and priv.stm (in Mailbox Store), and pub.edb and pub.stm (in Public Folder). Corruption in either of the four files stops the Information Store service and leads to inaccessibility of all the data stored in the Exchange Server database. Few main causes for file corruption could be improper server shutdown, header corruption, anti-virus scanning, and malicious software like virus. To overcome file damage situations and access the data saved in MS Exchange database, you will need to repair using an inbuilt repair utility named 'eseutil/p'. This utility, although successful in most cases, can fall short when the database is severely damaged. For such situations, the user is not left with any other option, but to search for a powerful Exchange Repair application.

To elaborate the above situation, consider a real-time scenario wherein you have a MS Exchange database of around 300 GB. The database (priv.edb file) gets corrupted and you also fail to roll back. To resolve file corruption, you run 'eseutil/p' utility. The repair process was successfully repairing the file, until it stopped and displayed the below error message:

“Assertion Failed: dPercentage >=0, file G:\ese97\src\eseutil\edbutil.cxx, line 563.”

After the above error message flashes on the screen, the repair process stops, resulting in complete inaccessibility of MS Exchange database. Additionally, the same error message appears every time you use 'eseutil/p' utility to repair the database.

Cause:

The root cause for 'eseutil/p' utility failure is severe corruption in priv.edb file.

Resolution:

To get past the above error message and to overcome 'eseutil/p' utility failure, you will need to follow the below mentioned steps:

1. Use a complete and valid backup to perform restoration of the database. 2. However, in situations where no backup exists or backup falls short in restoring required data, you will need to use a commercial Exchange Server Repair application. Such Exchange Server Repair tools use safe mechanism for repairing the database to maximum possible level. These tools can be used by any computer user, irrespective of its understanding about database repair.

Exchange Repair Software safely repairs MS Exchange database files (priv.edb and pub.edb) after every logical corruption scenario. The read-only Exchange Server Repair tool makes the original database intact. Supported by MS Exchange Server 5.5, 2000, 2003, and 2007, the tool is designed for Windows 7, Vista, XP, 2003, and 2000.