Fixing Error -1811 in MS Exchange Server

 While operating MS Exchange Server, you may get a message indicating that a processing error has taken place internally. You can try doing Exchange Server Recovery to resolve this problem by restarting the ESM (Exchange System Manager) or MS Exchange Information Store service, or both. Another error message can be related to Messaging Application Programming Interface (MAPI). OpenMsgStore call of Exchange Server may fail, and “The Microsoft Exchange Server computer is not available. Either there are network problems or the Microsoft Exchange Server computer is down for maintenance.” error message may get displayed.


Error -1811 is mostly shown when the Server operation to move file "E:\Program Files\Exchsrvr\mdbdata\E00.log" to "E:\Program Files\Exchsrvr\mdbdata\E000080A.log" fails, and a system error 2 (0x00000002): "The system cannot find the file specified."The move file operation will fail with error -1811 (0xfffff8ed). eseutil (4724) Error -1811 (0xfffff8ed) occurred while opening logfilename drive:\Program Files\Exchsrvr\MDBDATA\E00.log is displayed.

Another error message possible is “Unable to create a new log file because the database cannot write to the log drive. The drive may be read-only, out of disk space, misconfigured, or corrupted. Error -1811”.

Reasons for Error -1811

Possible reason behind Error -1811 may be that the log file signature and lGeneration line of the header in the E00.log are not matching. If the signature does not match, the information store of MS Exchange will not be mounted.

Another reason may be that you have scanned your system by an antivirus program and it has deleted or moved the exchange log file to vault. If this is the reason, you can resolve the issue by applying the underlying method.

•     Configure the installed antivirus, so that it does not automatically scans the MS Exchange Server folder in hard disk at any time.
•     If MS Exchange files were scanned by the antivirus, visit the antivirus log files to find out, whether the Exchange files were moved to vault or deleted by the antivirus. If the antivirus log file suggests that Exchange log files were deleted or moved then you can recover them from a backup file.

Recover Log File if they were Moved to Antivirus Vault

If Exchange log file was moved to vaults by the antivirus, perform the underlying steps for EDB repair

•     Restore the Exchange log to the folder containing production logs.
•     Start MS Exchange Information Store service. Exchange database will mount if no log files are missing. If any one of them is still missing follow the above process and recover the missing ones. After all the server log files count up to the actual number, database will be successfully mounted. 

Recover Log File if they were Deleted / Inconsistent 

If the Exchange log file was deleted or moved from its original place, it can be restored back from a backup taken earlier. To use a backup file for the purpose of EDB repair,

1.     Take a backup of the inconsistent Exchange databases to avoid any causality.
2.     If E00.log file has been created take its backup along with E00.chk file.
3.     Take a backup of all the log files to a folder.
4.     Rename last E00*.log file to E00.log.
5.     Restore database from backup. Replay the log files. Your Exchange database is now consistent. Some data may be lost in the process.
6.     Mount the database by starting Information Store service.

If you have not taken a backup, then you can first try using eseutil for EDB repair, to bring the database to consistent state and then recover EDB file.

If the above solution does not solve your problem, you can try Exchange Server Recovery software. Click here to download it