|Component:||Microsoft Exchange Extensible Storage Engine|
|Message:||<process name> (<process id>) <storage group name>The log range read from the file “<file name>” at offset <value> for <number> bytes failed verification due to a range checksum mismatch. The read operation will fail with error <error code>. If this condition persists then please restore the logfile from a previous backup.|
You might not be able to mount an Exchange database. Alternatively, you might not be able to successfully perform an online backup of an Exchange database or you might not be able to successfully complete an online restore of an Exchange database.
A transaction log has become corrupted. If the problems in the log file are only torn writes, they will be corrected by the Jet engine. If the problems cannot be repaired, the database rejects rather than applies the data, logging an event in the application log similar to the following:
The log range read from the file path\logfile failed verification due to a range checksum mismatch.
This issue can occur if the log mentioned in the event has become corrupted. Exchange cannot repair damage to log files because of factors other than torn writes, which will be fixed automatically by the ESE engine. Hardware failures that randomly damage a log file cannot be overcome because the obliterated data cannot be reliably reconstructed. ESE Event ID 477 indicates damage that cannot be repaired.