Summary: Exchange error 501 is associated with problems within the server’s Jet database engine. When this error arises, users can face issues like database mounting problems. While the primary reason behind the error is corrupted log files, other reasons can also trigger it. Stellar Repair for Exchange is a tried and tested product that gives superior EDB repair results in such a scenario facilitating a quick database mount thereby bringing the server back online.
Microsoft Exchange Server is composed of many components, each having their own vitality. The Jet Database Engine and Transaction Logs are two inconspicuous, yet essential aspects of the whole Exchange setup. Any glitch in either of them and the functioning of the entire server can get disrupted.
Take the case of Exchange 501 error for example. This error is associated with the message “JET_errLogFileCorrupt” and it arises if some critical transaction log files become corrupt before they have been committed to the database. The effects of the error include the database being marked as inconsistent state or in “dirty shutdown” state, EDB file mounting issues, and subsequent halt of all server activity.
Let us shed some light on why this Jet database engine arises and how users can resolve it.
Exchange 501 error and its causes
The JET_errLogFileCorrupt error or error 501 of the Exchange server is generally observed when users try to mount an Exchange database after some kind of disaster like a sudden power outage. When the Exchange server gets terminated unexpectedly, multiple transaction log files that haven’t been committed to the database can easily become corrupted. Damage to these files causes failure of any further attempts to commit them to the database, which in turn causes the database to be marked as inconsistent. And when that happens, it can lead to a halt in all user activity and even permanent mailbox inaccessibility. Other reasons for log file corruption include:
Log file header damage
Bad sectors on the server’s hard drives
Technical or mechanical faults within the server
Usually, if the Exchange server is marked as inconsistent, administrators try to recover the database from a previous backup or from previously committed log files in order to bring it back to a consistent state. But this technique cannot be adopted if corrupted log files themselves are the reason behind the database’s inconsistency. In such a scenario, other more advanced solutions are needed to get rid of the problem.
How to fix Exchange error 501
Try one of the below mentioned manual techniques to resolve this error:
Move everything other then the EDB files into a temporary folder and then try mounting the database
Check the status of the log files by running the command eseutil /mh in the server’s command prompt. If the operation terminates with error 501 JET_errLogFileCorrupt message it means the log file is damaged. Follow the below mentioned steps to fix the error:
Locate a working backup of the corrupted log file
Delete the damaged log file and recover it from its backup. When the log file is restored from the backup, a temporary file called restore.env is created which stores all logs that have not been committed to the EDB yet.
Once this file is created, run the command eseutil /cc “Path of the restore.env” to fix log file issues.
Delete the temporary file ‘restore.env’.
Note: This technique can work only if you have a recent valid backup of the log files that have been corrupted.
Drawbacks of these manual methods
While these methods work if all required preconditions are met, they suffer from a few inconvenient drawbacks:
The approach is lengthy and tedious
Performing these steps needs proper caution and prior technical knowhow
To use this approach a proper installation of Exchange server and the availability of a recent relevant backup is mandatory
In case of any errors while following this method, the server can be negatively impacted
A better, safer approach
If you don’t have a valid backup to restore log files or if you’d like to overcome the limitations of the manual method by opting for a more efficient approach, you should try using reliable third-party Exchange server recovery software Stellar Repair for Exchange. Backed by powerful repair and recovery algorithms, this product scans Exchange EDB files and repairs them quickly to facilitate easy data recovery from them. It enables users to recover dismounted / offline EDB files and also supports simultaneous repair for large and multiple files. Moreover, you can also use it to export recovered mailboxes to Live Exchange Server and Office 365. In times of Exchange troubles, this application is undoubtedly the ultimate remedy.
To sum it up
Corruption of transaction log files can sometimes get too tough to handle, especially when you are limited by manual methods. Switching to reliable, safe, and accurate third-party automated solutions is the best way to save your time and effort and also fix errors flawlessly.
Check what our MVP has to say about Exchange Recovery from Stellar.