%1 (%2) %3 The database page read from the file “%4” at offset %5 (database page %10) for %6 bytes failed verification due to a page checksum mismatch. The expected checksum was %8 and the actual checksum was %9. The read operation will fail with error %7. If this condition persists then please restore the database from a previous backup. This problem is likely due to faulty hardware. Please contact your hardware vendor for further assistance diagnosing the problem.

ESE Event ID 474 indicates that a database page read failed verification due to a page checksum mismatch. This essentially means that the particular database page referenced within the Microsoft Exchange Information Store service file named (such as priv1.edb) is corrupt. Possible symptoms are as follows:

• Users cannot send or receive e-mail messages.

• You cannot start Microsoft Outlook on your client computer.

• Online backups fail to complete with a -1018 checksum error.

• Online defragmentation reports a -1018 checksum mismatch error.

This error is typically the result of a hardware malfunction. The associated checksum mismatch -1018 error indicates some type of hardware error 99% of the time.

To resolve this error, do one or more of the following:

• If the error code listed in the event description is -1018, review Microsoft Exchange Server Analyzer article ESE 474 -1018: Unrecoverable Error Detected in Database.

• Run system diagnostic tests. These tests may not be conclusive if the problem is infrequent and transient or only appears under very complex loads.

• Consider migrating to different hardware.

• Upgrade disk controller BIOS and firmware to the latest vendor revisions.

• For more information, see 314917, Understanding and analyzing -1018, -1019, and -1022 Exchange database errors.

• Repair the database with the eseutil /P, followed by eseutil /D and then isinteg -fix.