Let’s say, we have an Exchange Server, which has suffered a power failure during the installation of a Cumulative Update. In this post, we will discuss how to recover the Exchange Server data using the third-party application, named Stellar Repair for Exchange.
The Scenario and the Issue
We have an installation including a virtual machine hosting Active Directory, DNS, and DHCP. On another virtual machine, we have an Exchange Server 2019 with 3 mailbox databases. Both virtual machines are running on Windows Server 2019 with the Active Directory Forest and Domain functional level set to Windows 2016.
We perform routine maintenance, normally on a monthly basis where updates are installed and other maintenance tasks are performed, like hardware upgrades. During a routine maintenance while installing the Cumulative Update (in this case Cumulative Update CU12), there was a power cut and the Hyper-V host lost power before securely shutting down the VMs.
After the power was restored, the Hyper-V server was powered on and the virtual machine of the Active Directory (ADS001) started successfully. The Exchange Server (SRV01) was also started with no issues. After a while, the users started complaining that they couldn’t access their data and mailboxes.
After investigation, it was found that the installation got corrupted as the Exchange Server Cumulative Update (CU) failed in mid-installation. Due to this, some of the services of Exchange Server were failed to start.
Recovering the Server
Since the operating system is still booting, there is an option to restore the Exchange Server installation using the Exchange Server setup files. For this, we need the exact installation files that correspond to our Exchange Server. However, there is no guarantee that the Exchange Server installation will be repaired with the native tools. We need to also consider the health of the data.
To start this, we need to run the installation setup (see below).
D:\Setup.exe /IAcceptExchangeServerLicenseTerms /PrepareAD /OrganizationName:”<organization name>”
This command will reset the permissions, recreate all the needed requirements for Exchange, and hopefully repair the installation of the Exchange Server. After this process, we need to restart the server.
This might not work or partially work. Partially work means that the Exchange Server is now working, but there is a problem with the databases, which remain unmounted. When we try to mount the database, we get a dirty shutdown issue.
We can run the ESEUtil command with soft recovery to try to fix small corruption. If this fails, another option is to run hard recovery. However, this is not recommended by Microsoft as it will purge any data that is deemed corrupted. There could be false positives and you need approximately the same size of free space as of the databases. Apart from this, this operation could further damage the database with no recovery. Also, Microsoft will not be liable to support if the hard recovery is executed on the database.
The only other option is to recover the whole server from last day’s backup. But our backup was not updated and two days backup was missing. The alternative solution is to use a third-party application.
We decided to try Stellar Repair for Exchange – a third-party Exchange Server Recovery application for repairing and recovering corrupt databases.
The way forward
- Take a copy of the EDB files somewhere safe, like a NAS or backup storage device.
- Re-install the Virtual Machine with the same Computer Name and IP, and hard drives.
- Run the installation of Exchange Server with /Mode:RecoverServer to do a fresh installation of the Exchange Server and recover the configuration (except the receive connectors) from the Active Directory Schema.
- Recover the database using Stellar Repair for Exchange, create new Exchange Server database, and then export the recovered database to the new server database.
Using Stellar Repair for Exchange to Recover the Database
Stellar Repair for Exchange can recover database, with no data loss. The installation of the application is straight forward and relatively small, with the installation process takes about 3 to 5 minutes.
After the installation is complete, open the application. It immediately asks to select the database to restore from. It offers options to manually browse to the database or use the Find button. There is no limit on size of mailboxes.
Once the file is selected, select the type of scan – a quick scan or an extensive scan.
Depending on the size or damage to the database, it takes some time. After the scan is complete, it allows to save the scan. This means that after closing the application, we can reopen the scan and have access to the database immediately.
On the left pane, the entire structure of the database/s is displayed. In the middle pane, it shows the list of emails, and in the right pane, it displays a full HTML preview.
The middle pane also provides a search function where we can do in-line search.
Apart from that, the application features more criteria to search from.
At the bottom of the left pane, it provides buttons to switch between Calendar, Contacts, Tasks, Journal, and Notes.
The application has a powerful and extensive interface, but the best thing is the export features.
We can export to PST or other file formats and also directly to Office 365. For this post, we will export to a live Exchange Server.
Exporting directly to a live Exchange Server database is the ideal recovery in this scenario. It features automatic or manual mailboxes matching, prioritize mailboxes recovery for important mailboxes, parallel recovery to boost performance, and continuation in case of interruption.
With Stellar Repair for Exchange, we are able to recover damaged database. It lived up to its reputation and ultimately helped us in recovering Exchange Server in the least possible time with no data loss. The best features are prioritize and parallel mailboxes recovery that make recovery fast and easy.