When you try to mount a user database on Exchange Server, you may come across Exchange Error 1811 corresponds to JET_errFileNotFound. The following message will appear on your screen-
An internal processing error has occurred. Try restarting the Exchange System Manager or the Microsoft Exchange Information Store service, or both.
ID no: c1041724
Exchange System Manager
You will get following events in the Application log-
Event ID: 486
Description: An attempt to move the file "E:\Program Files\Exchsrvr\mdbdata\E00.log" to "E:\Program Files\Exchsrvr\mdbdata\E000080A.log" failed with system error 2 (0x00000002): "The system cannot find the file specified." The move file operation will fail with error -1811 (0xfffff8ed).
Event ID: 455
Description: eseutil (4724) Error -1811 (0xfffff8ed) occurred while opening logfile drive_letter:\Program Files\Exchsrvr\MDBDATA\E00.log.
Event ID: 413
Description: Unable to create a new logfile because the database cannot write to the log drive. The drive may be read-only, out of disk space, misconfigured, or corrupted. Error -1811.
However, there is following causes responsible for the error in Exchange Server during mounting the database, but the key reason could be the inequality signature and LGeneration. If the Exchange log file (E00.log) has mismatching signature, you cannot mount the database even if the database is consistent. To resolve this, contact Microsoft Product Support Services (PSS) at http://support.microsoft.com
Another cause is accidentally deletion or quarantines of Exchange log file by Antivirus software. To resolve this, first you need to examine the configuration of antivirus software-
Double-check that the antivirus is not scanning Exchange directories. Check the guide to get the information about how to check and configure antivirus to work together with Exchange Server. https://support.microsoft.com/en-us/kb/823166
Now review Antivirus software log file to verify Exchange log file has been deleted or quarantined, and try to recover Exchange log file using following methods-
If Exchange log file has been quarantined...
First, recover Exchange log file to the production log folder and start Microsoft Exchange Information Store service. Now your database will be mounted if there is no more missing log file, but if there is few other missing log files; check missing log file in quarantine folder of the antivirus software. But in case if you cannot locate those missing log file in quarantine folder, try the below method-
If Exchange log has been deleted…
As you didn’t find log file in quarantine folder of the antivirus, it means log file is deleted. Now restore storage group database from backup.
Copy all unstable databases to backup folder. If new Exchange log file E00.log has been created, copy this file and all other log file to the backup folder including E00.chk.
Now change the name of E00*.log to E00.log and restore database from the backup. This method brings your database to consistent state and now this database can be mounted on Exchange Server.
But in case if there is no backup or you cannot restore database from the backup, try Stellar Phoenix Mailbox Exchange Recovery software to extract inaccessible and selective Exchange .edb file and bring it to consistent state. That’s it.