Disaster Recovery – CAS & UM Server

In my previous article Disaster Recovery – Mailbox Server I have explained the term of disaster recovery and came to know the importance of disaster recovery.

In this article we will see the disaster recovery for client access server and unified messaging you might be wondering that why I have added the unified messaging in this article it is simple first is that there is not much data need to recover while considering unified messaging and second thing is that I don’t have much idea to go for it except the theoretical knowledge.

                                                    Disaster Recovery – Client Access Server
 Before the release of Exchange 2007 it was quite simple to take the information of exchange server as mode of backup, rebuild the server and restore the data because all the stuff are stored in the single server itself. There were no fundamentals which will separate the roles into different server as like we have in Exchange 2007. And most of the configuration data are stored in Active Directory itself. So in real time we won’t actually need to take the backup the client access server. But let say if we modify some settings in the CAS for exchange 2007 mailboxes like OWA authentication in that scenario I guess we might require to have the good backup. As I said earlier whenever we make any changes in the exchange server we should have the backup of it and need to know how to restore it back.

Here inorder to  explain you in better way I took the example of OWA authentication method, it might be simple task to reset it back but my idea here is to show the backup strategy of CAS which is a new feature in Exchange Era. And how to restore it in the new server.

Which are the files need to backup:
- System State Backup
- IIS Metabase Backup
- CAS Backup.

Note: Whatever you are taking the back in the IIS metabase it is more then sufficient but let say your server get crashed and bought new server you will get default IIS setting but what about CAS setting – need to be remodified back as per the requirement. By following the below steps atleast you can recover some of the configuration in terms of OWA.

So lets start :

Let say my company completely migrated to pure Exchange 2007 and all the users having their mailbox in 2k7. So when they require to access the owa simply they can type https://webmail.domainname.com/owa This /owa indicates that the user mailbox is in 2k7. so by default it will open the new GUI page where I will see domain\user window. But my company doesn’t want to have this page instead of that they want normal authentication page what we use to had in Exchange 2003. Will can it be done, yes we can do it but for that we need select normal authentication method instead of form-based authentication.
Figure1:


Now I have made changes in my CAS server so I need to take the backup of OWA virtual directory because the changes which I made is for OWA 2007.

Right now I will show you how to take the  backup of the IIS configuration from the CAS server by executing the following command:
get-owavirtualdirectory “owa (default web site)” | export-clixml owa.xml -depth 1

Save the owa.xml in a secured location.

If you see the above command, we are taking the information of owa virtual directory by executing the command get-owavirtualdirectory and the name of owa virtual directory for which we are taking the information is : owa (default web site) and then finally we are exporting the information in to a XML file called as OWA.xml

One fine day my server got crashed so I bought new server with the same information.
Inorder recover the CAS server : we need to run the following command
Setup.com /m:RecoverServer or Setup.com /Mode:RecoverServer
Figure 2:


Let me show you my default owa setting
Figure 3:


Go to bin directory of Exchange Server application
Copy the owa.xml (this is the file which has old setting)
Open a notepad and paste the following script and Save it as “RestoreVirtual.PS1”
Now open the Exchange Management Powershell command
Route it to bin directory
Type the following command
 RestoreVirtual.PS1 owa.xml
Note : As you all know that we have default OWA already existing in the CAS server and if we run RestoreVirtual.PS1 owa.xml, it will throw the error message informing that OWA is already exist
Figure 4:


So it is very important to remove the existing OWA from CAS Server
So inorder to do that:
 Open the powershell
 Get-owavirtualdirectory
 Remove-owavirtualdirectory –identity “OWA (Default Web Site)”

Now we can go with RestoreVirtual.PS1 owa.xml Figure 5:


After this we need to restart the IIS by executing the command “iisreset /noforce”

Now lets take a look into to the property of OWA (default web site) CAS virtual directory from the Exchange Management Console : Figure 6:

You can see that it took the old setting what I had before.

If I try to access OWA it will open the modified viewable setting what I had before.  Figure 7:

This is how you can restore your OWA virtual directory.

Ok this is what about the owa virtual directory. Well if you see CAS server we have other 3 virtual directories also – Exchange (default web site), Exchweb (default web site) & Public (default web site). You might be having the question what will happen if we try to take the backup of these 3 virtaul directories like :
get-owavirtualdirectory “exchange(default web site)” | export-clixml exchange.xml -depth 1
get-owavirtualdirectory “exchweb (default web site)” | export-clixml exchweb.xml -depth 1
get-owavirtualdirectory “public (default web site)” | export-clixml public.xml -depth 1

Will it create a backup file called as .xml for the above one, the above file are exchange 2003\2000 supported file and as far as backup is concern Yes it will take the backup.

Ok now the next question would be how about restore method, do I need to delete the existing virtual directory which has been created for the above 3 virtual directories and restore it by following this command :
Restorevirtaul.ps1 Exchange.xml
Restorevirtual.ps1 Exchweb.xml
Restorevirtual.ps1 public.xml

You can do it but it won’t effec or take the old setting back to the new server as like we did for owa virtual directory. Eg: as like OWA (2007) set to standard authentication, let say you have did the same setting changes in other 3 virtual directory and rebuilt the server then restored the .xml. Even you restore first it will prompt you error message
“Exception setting “DirectFileAccessOnPublicComputerEnabled” and for Private computer Enabled can only be done for Exchange 2007 Virtual Directory.

And if you see the setting in Exchange Virtaul Directory => Properties : It will possess the only default setting what we had at the time of rebuilding.
Figure 8:


Reason I found so far or in other I believe is that : when we are restoring OWA.xml we are running one script i.e RestoreVirtual.PS1 OWA.XML. This PS1 is the script which is purely created for OWA (Exchange 2007) virtual directory and not for other 3 virtual directories. So that’s it can’t be used for Exchange, Exchweb and public virtual directories.

If anybody aware of how to restore the other virtual directories through powershell please let me know. As I told you before that if we have metabase backup then we can restore all the virtual directory information.

I guess it has given fair idea about how to take backup of owa virtual directory. Here is the one table which talks about files need to be backed up for CAS

Table 1   Locations used by the Client Access server role for configuration and end-user data

    

                                                                Disaster Recovery – Unified Messaging

As like CAS, Unified messaging configuration data is stored in Active Directory so there is not much requirement to take the backup unless and until you make any changes but however you can take the file backup of the following folders
- system state backup
 C:\Program Files\Microsoft\Exchange Server\UnifiedMessaging\Prompts
C:\Program Files\Microsoft\Exchange Server \UnifiedMessaging\temp

For disaster recoery you can follow this command : setup.com /m:RecoverServer.

Note: For unified messaging I am not able to get much information for you. If you want to know the about the unified messaging please log into Microsoft Technet and msexchange.org.

I hope this article is being informative for you. Thanks for sharing your time


Related Link:

Disaster Recovery – Mailbox ServerDisaster Recovery – Client Access Server & Unified Message
Disaster Recovery – Hub Server and Edge Server


Reference Link:

Configuring Exchange Server 2007 Preview - Chapter 9: Disaster Recovery with Exchange Server 2007 
Client Access Server Data