Exchange 2010 CAS server Disaster Recovery

If your CAS fails due to an irreparable hardware problem; follow these steps to repair it:

1. Reset the client access server’s computer account within the Active Directory Users and Computers console. Do not delete the account.
2. Install Windows on the new server and then install the same OS version as the failed server.
3. Rename the server to match the name the CAS used and join the server to your domain.
4. Depending on the version of Exchange Server and service pack you were running, insert the corresponding installation media into the server and run the following command:

Setup /m:RecoverServer /installwindowscomponents

5. After the command runs, Setup will install the Exchange binaries and use the information stored in Active Directory to rebuild your CAS.

Note: This technique can also be used to rebuild any other Exchange Server roles, except for the edge transport server.

These steps work well to rebuild a failed client access server; however, there is a major caveat. This method only works if the server is running a standard configuration, which is unlikely since many organizations personalize their Outlook Web Access interface.

Using these steps will rebuild the CAS to a functional state, but any OWA customizations will be lost. This happens because Setup copies the Exchange binaries from the installation media, not your customized files.

This i have tested and working solution for CAS server Role.