Having a high availability scenario helps a lot where a server outage will not affect your end-users. The steps that we are going to follow in this article are applicable for both type of scenarios: single servers and multiple servers in high availability mode.
Before validating the steps required in order to restore from a complete server failure, we need to review the Exchange Server 2013 roles, in this version we have three roles: Client Access, Mailbox and Edge Server. The focus of this article will be on the roles that are located in the internal network which are Client Access and Mailbox Server roles.
When recovering from Client Access Server roles failure then there are fewer steps, because the server itself does not have any data that needs to be restored. When restoring the Mailbox Server role we need to follow the same steps of a Client Access but an additional set of steps will be required to recover from the Mailbox(es) Database(s).
Like the previous versions of the product, most of the information required for an Exchange Server resides on Active Directory, and for that reason, the restore process is a simple procedure.
Recovering from a server failure…
It is all about planning, being prepared and trained so when a disaster strikes you can get over the issue as quick as possible. It is not a requirement, but here are some key items that should be documented/validated when the Exchange Organization is running (an update of these key points when there is a change in the production environment it also important for documentation purposes):- IP Configuration
If you use the same IP address and the exact number of adapters, then we will have less chances for an issue during the restore process. The main reason is that other components, such as Firewall, Load Balancer and DNS are using that specific IP. - Windows Operating System (version and Service Pack)
It is not supported to restore to a different Operating System, so we must keep the same Operating System on the new server. - Exchange Server version
Knowing the Exchange version will guarantee the administrator to restore the exact same version during the restore procedure. - Exchange Server installation path
Keep it simple, if you use default values during the first installation, then it is one less thing to worry about when restoring Exchange Server. If you have used a different path, then make sure that you remember the path because you will need to specify this during the restore process. - Exchange Server Volumes (applicable on the Mailbox Servers)
Make sure that all the volumes used by Exchange are available on the replacement server. - Certificates installed on the server and their association
We can always recreate or rekey the certificates, but if you have them documented that will save you some time. - Test the procedure in the LAB
Be realistic, measure the time to restore the information and document all steps. That will be key to define the time required to restore the environment. - Third-party software installed on the server
- IMAP/POP3 configuration (service)
These services are configured after the server installation and they will not be restored on the new server. - Registry information
The process to recover a server will not bring any information that was configured on the registry of the original server. Any special customization has to be added again on the new server. - Physical and Virtual
When recovering a server, you can recover a physical server in a virtual server, as long as your VM is following the Microsoft best practices - OWA Customization
If you have any OWA customization, then you will need to restore those settings. - Anti-spam features
The anti-spam agents must be installed on this new server.
Preparing the new server for the recover process…
The first step is to install the requirements on the Operating System, for this article our original server was running on Windows Server 2012 R2. If you have documented your Exchange Server deployment, then that is the same procedure. In our case, we are going to run this cmdlet and after installing all the features, we will then restart the server.Install-WindowsFeature AS-HTTP-Activation, Desktop-Experience, NET-Framework-45-Features, RPC-over-HTTP-proxy, RSAT-Clustering, RSAT-Clustering-CmdInterface, RSAT-Clustering-Mgmt, RSAT-Clustering-PowerShell, Web-Mgmt-Console, WAS-Process-Model, Web-Asp-Net45, Web-Basic-Auth, Web-Client-Auth, Web-Digest-Auth, Web-Dir-Browsing, Web-Dyn-Compression, Web-Http-Errors, Web-Http-Logging, Web-Http-Redirect, Web-Http-Tracing, Web-ISAPI-Ext, Web-ISAPI-Filter, Web-Lgcy-Mgmt-Console, Web-Metabase, Web-Mgmt-Console, Web-Mgmt-Service, Web-Net-Ext45, Web-Request-Monitor, Web-Server, Web-Stat-Compression, Web-Static-Content, Web-Windows-Auth, Web-WMI, Windows-Identity-Foundation, Telnet-Client, RSAT-ADDS
The second step is to download and install the Microsoft Unified Communications Managed API 4.0, Core Runtime 64-bit. The installation process is straight forward (Figure 01 shows the first page of the installation wizard), we will use default settings to complete the installation.
Figure 01
The last step is to use the same Exchange version that we had in the original server. If you have another Exchange Server in the environment, the following cmdlet can be used (Figure 02)
Get-ExchangeServer | ft Name,ServerRole,AdminDisplayVersion –AutoSize
Figure 02
The next step is to identify which is the Cumulative Update of the failed server. We need to compare the output of the AdminDisplayVersion with the Build number (Figure 03) and on the same page, we can download the right version (the page that contains all Build Numbers is listed at the end of this article).
Figure 03
After downloading the same Cumulative Update that was installed in the production server, the next step is to extract it into a folder on the system drive (in this Tutorial we are going to use C:\EXCU6 folder).
Recovering the Exchange Server…
We have an environment for this article with 2 (two) servers: QC-EX01 and QC-EX02. The server QC-EX02 had a server failure and we need to restore the server on different hardware.At this point, the server original QC-EX02 is offline, and we have a basic documentation from the previous Exchange Server and we have a new server that has all the pre-requisites installed on it.
The first step is to reset the computer account in the Active Directory, open Active Directory Users and Computers, right-click on the Exchange Server computer object that we will recover, and click on Reset Account (Figure 04), click on Yes to confirm, and then OK.
Figure 04
Now our attention is on the temporary server, we must perform these tasks to this new server:
- Check if the disk layout and network adapters are the same as we used to have in the production server
- Assign the same IP address to the new server
- Rename the new server with the same name of the failed Exchange Server (in our article is QC-EX02) and restart the server
- Join the new server into the domain
Cd .\EXCU6
.\setup.exe /m:RecoverServer /IAcceptExchangeServerLicenseTerms
The results of the command above is shown in Figure 05, and after checking that steps have the COMPLETED, then that is a good sign that the recovered Exchange Server is back and almost ready for the primetime.
Figure 05
If you have only the Client Access server role installed on the server, then you just need to work on the points listed below and after that our restored server will be ready.
- Install the Exchange Certificate (you can import from an existent server or recreate them using an Internal CA/Public Certification Authority) and assign the services accordingly
- If you were using POP/IMAP service, make sure that you configure the services to be automatic
- Restore any OWA customization that you had in the original server
- Install third-party applications that you had in the original server
- If you were using built-in anti-spam agents, then you need to reinstall them on the new server
Figure 06
Conclusion
In this article, we went through the steps to recover an Exchange Server 2013 using the information stored in the Active Directory.More information:
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