subject: Symptoms, Reasons, and Solution of Physical Exchange Database Corruption [print this page] Author: Axel Culver Author: Axel Culver
Microsoft Exchange Server first passes data to the operating system and then, depends on the installed device drivers and hardware to keep this data securely. In case, these lower layers fail to provide required protection to data, your Exchange database might become corrupt. This form of database corruption is counted as the most severe one since it lacks the ability of get repaired and compel you to restore the database from backup or delete the corrupted data using Eseutil hard recovery techniques. Another alternative can be to use an Exchange Server Recovery utility that provides mailbox extraction from the corrupted database.
Most of the physical database corruption errors are detected by Exchange Server while operations like taking an online backup or performing database maintenance. This is because during these operations, the database engine undergoes page-wise testing of database. As a result, it logs similar errors, as mentioned below, in application event log:
1. "-510 JET_errLogWriteFail"
2. "-1022 (JET_errDiskIO)"
Cause
Each Exchange database has a 40-byte header information that stores a page number a CRC (Cyclic Redundancy Check). The database engine first determines the page number to ensure the requested one and then, checks the CRC value when reading the database page. If either of these checks fails, an error is returned, as above. Before declaring the corrupt page, the database engine attempts to read it up to 16 times. These error indicate that either the page is bad or the database engine has failed in its trials without any success. You cannot backup the database in such cases and the operation is aborted. Solution
You can avoid such problems by configuring a suitable hardware, device drivers, and firmware. Possible solutions to these problems are:
1. Restore from a backup, if is available and valid
2. Run eseutil /r command to find and remove bad pages from the database
The lost database pages might contain data that is important. For example, if the deleted page contains a B-tree index, it can render a considerable database part to become useless. To prevent from such situations, it is however, recommended to opt for safer Exchange Recovery solutions. The Microsoft Exchange Recovery software use intensive, yet safe, scanning algorithms to repair and restore the corrupted Exchange database.
This Exchange Recovery Software is a reliable tool that repairs corrupted Exchange database and restores the mailboxes in *.pst files. The Exchange Recovery utility supports MS Exchange 5.5, 2000, and 2003. The tool has an interactive interface that makes the software easy to operate. The tool is compatible with Windows 7, Vista, XP, 2003, and 2000.About the Author:
Axel Culver has passion for writing Technical article. He is right now writing articles related to Product like Microsoft Exchange Recovery Tools and PST Recovery Software for MS Outlook. He is a professional writer and has written many blogs, article, press releasing and content for many websites.
