Exchange database gets corrupted due to many reasons such as, missing log files, deleted log files, or uncommitted log files are among the most common ones. In case of uncommitted logs, you can replay the files to recover the Exchange database. However, in case of missing log files, you may proceed with hard recovery, while keeping in mind the risk of data loss.
If steps to recover exchange database do not work, using third-party EDB recovery software would be advisable. Prominent of these tools include Stellar Repair for Exchange software.
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Exchange log files and their importance
The Exchange database (EDB) files store the user’s mailboxes, and the contained log files include transaction details (such as data modifications). During the write-ahead logging (WAL), the log files record all the transaction details before they are applied to the database. If the database goes corrupt, these log files help to recover the transaction. Missing or deleted log files make it difficult to recover the Exchange database and can lead to a Dirty Shutdown.
Steps to Recover Exchange Database without Log Files
You should make sure to back up your database before starting an Exchange Database recovery method. Professionals often use ESEUTIL tool for recovery, but it is not foolproof. Here are the steps to recover the Exchange database.
Check the database state
Running the Eseutil command helps to verify, defragment, and recover the damaged Exchange database files. Follow the below steps.
- Run the command eseutil/mh
- A Clean Shutdown status will indicate no need for log files
- Mount the database to the Exchange server
- A Dirty Shutdown status will require the need for log files to recover the Exchange database
Soft recovery
If the database shows Dirty Shutdown state, you may proceed with a soft recovery. For this, copy-paste the missing transaction log files from the back up to a folder in the directory of Exchange Server. Run the cmdlet eseutil/r to replay the log files to the database.
ESEUTIL /r enn /L [path to log files] /s[path to checkpoint file] /d[path to database file] /i
Replaying of log files cannot take place in several conditions:
- Checkpoints indicate a wrong file
- Database files are missing for a particular storage group
- The log file has a modified path
- Log files belong to another database
Hard recovery
If your log files are missing and the Exchange database is still in the state of Dirty Shutdown, you may proceed with hard recovery. This method is effective in case of corrupted log files or a missing sequence. If Eseutil fails to recover data from EDB during a hard recovery, it can lead to permanent loss of data. Due to this uncertainty, admins consider it as the last option to recover data from Exchange Server.
To perform the hard recovery, you can execute the Eseutil command with the following parameter:
eseutil/p ‘Database path’
Limitations with Eseutil
- Data can be permanently lost
- As discussed, there is no guarantee of data retention by using Eseutil command. During the recovery process, it may delete the changes made to mailboxes because of uncommitted logs. It may also eliminate the irrecoverable information, causing permanent data loss. Creating a backup before performing this operation will be preferable.
- Command requires lots of free space to execute
When running the Eseutil command for the hard repair of the corrupted database, you need to free up at least 1.2 times of the space consumed by the database. Mostly, due to the large size of the database, it becomes difficult to manage free space, which is a big drawback of this method.
- Inconsistency after running command
You would need to run isinteg command to get away with the inconsistency caused due to eseutil utility. At times, the command does not remove the errors completely, which compels you to run isinteg command frequently.
- Time consuming
Eseutil command consumes considerable time to execute especially in case of large-sized databases. You should think of it only if you have ample time to spare.
- Complex process
Multiple commands related to GUI and Powershell make working Eseutil utility too much complicated. Even if an experienced professional, there is always the possibility to stuck up when working with this command.
Recover Exchange Database with Stellar Repair for Exchange
To avert the shortcomings in the recovery methods discussed, using Exchange Recovery software, such as Stellar Repair for Exchange will be ideal.
This tool overcomes the risks and limitations of manual methods. It also performs complete recovery of a corrupt, inconsistent, or damaged Exchange database without any data loss. The software works fine on Exchange Server 2019, 2016, 2013, and several other previous versions. Some of its prominent features include:
- Repair damaged Exchange EDB files
- Parallel processing for quick database recovery
- Converts Exchange database files to different formats
- Recover missing or deleted Exchange mailboxes
- E-discovery search and granular recovery
Here are the steps to recover Exchange Server database using Stellar Repair for Exchange:
- Download and install the software
- Launch the software and select the corrupted EDB file
- Select Quick or Extensive scan mode
- Browse through the database next to scan the following:
- Calendar
- Contact
- Tasks
- Notes
- Journal
- Click the Save button, choose PST, and then select the destination
You can create new database and then export all the recovered mailboxes from the corrupted database to the new database. For this, you just need to click on live Exchange Server. It will match the source and destination mailboxes automatically.
Wrapping Up!
When your database on the Exchange Server 2016 fails to mount or displays the state of Dirty Shutdown, it signifies the presence of an unhealthy log files in your Exchange database. This flaw occurs mainly due to uncommitted, corrupt, or missing log files.
To recover the Exchange database in such a situation, you may proceed with the soft or hard recovery by using the Eseutil command. However, these manual methods have certain limitations, such as the chance of data loss, Corrupted databases, the absence of Microsoft support, No guarantee for the manual methods to recover the exchange database. Using Stellar Repair for Exchange is among the best alternatives to take care of these flaws.
