Despite whether your Exchange organization is large or small, losing email services has a huge blow to your business. When disaster strikes your Exchange Server, your first natural feeling may be to reach for your backup. Though, restoring a backup may not be the best course of action for all time. That is because when a breakdown takes place, it is vital to restore the mail flow as swiftly as possible, and restoring a backup can be time consuming. It is generally better to restore the mail flow first, and restore the remaining data afterward.
However, a standard restore operation is certainly the favored way for recovering an information store, occasionally an organization's logistical requirements demand using diverse practices.
1. Rebuilding the Exchange Server infrastructure
When an Exchange Server breakdown takes place, the very first thing that you must perform is to recognize which server has failed and what functions that a server was hosting (supposing that the server is running Exchange 2007 or Exchange 2010). The configuration information for each Exchange Server function apart from for the Edge Transport Server function is saved inside the Active Directory. This makes it feasible to rebuild the server without restoring a backup as long as yours Active Directory is still operative.
The primary step you should take is to open the Active Directory Users and Computers console and reset the computer account that belonged to the failed server. But remember not to remove the computer account, otherwise it would not be possible to recover the server.
When the computer account has been reset, install Windows Server onto the failed server (or onto a replacement server). You should make use of the same Windows edition and the same service pack as what was operating on the failed server. Once Windows has been installed, you should change the computer name to match the name of the failed server. After performing this, connect the server to your domain. Once you connect the server to your domain, the server will presume the characteristics of the failed server.
Next, add your Exchange Server installation media into the server. Rather than executing a usual Exchange Server installation, open a Command Prompt window (navigate to the installation media (run the command given below:
The above command will restore the failed server in a few minutes. Once the server is rebuilt, make sure to install any omitted patches.
2. Restoring mail flow to the Exchange Server
If the crashed server was running any server role other than the mailbox server role or the edge transport server role, then you should be back in business. Though, if the breakdown takes place on a mailbox server, then the mailbox database may have been gone. The best thing to do in this type of circumstance is to execute a dial tone recovery.
A dial tone recovery is a method where you make a database filled with vacant mailboxes. That way, users can start sending and receiving mail without having to wait for hours or days while you restore their older messages.
The method for making a dial tone database differs somewhat depending on the version of Exchange Server. In Exchange Server 2010, you must start by making a vacant database using the New-MailboxDatabase cmdlet. For example, you might type:
New-MailboxDatabase --Name DialTone --EdbFilePath D:\Dialtone\DialTone.edb
Make sure to build the database in a location that has an abundance of free space as you will ultimately merge the user's old data into the database.
Once the new database has been formed, you must rehome your user accounts so that they point to the dial tone database. To achieve so, you must make use of the Get-Mailbox command to retrieve a list of all of the mailboxes that were saved in the failed database (this information is saved in the Active Directory). You must then use the Set-Mailbox cmdlet to rehome the mailboxes. For example, if your old mailbox database was named DB0 then the command that you would use is:
Get-Mailbox --Database DB0 | Set-Mailbox --Database DialTone
The final step is to mount the database; then the users will be capable to send and receive mail. You can mount the database by using the Mount-Database cmdlet. In this particular case the command that you would use is:
Mount-Database --Identity Dialtone
3. Recovering data from the Exchange Server
The final step in this procedure is - to recover your old data. The step you should take for this procedure differs as it depends on what version of Exchange you are making use of. In Exchange Server 2010, you have to form a recovery database, whereas In Exchange Server 2007, you have to form a recovery storage group. From there only, you would be able to restore the backup of your mailbox database to the recovery database or the recovery storage group. When the procedure gets completed, you will have to combine your recovery storage group or recovery database with any data that has been collected in the dial tone database. You can hit upon the guidelines for executing a dial tone recovery in Exchange Server 2007 and Exchange Server 2010.
At last, the steps that you will have to execute throughout an Exchange Server disaster recovery process will rely on the type of the breakdown. This article presumes that at least one Exchange Server has failed disastrously. If the breakdown is less rigorous, then you may be capable to leave out some of the steps that I have discussed in this article but if you are still unable to restore your Exchange mailbox items, then you should take help of professional exchange recovery software, that will definitely restore inaccessible mailbox items.