In the era we live in, everything runs on hardware. Whether you are a cloud provider or a company that runs its own hardware, we are dependent on this hardware and the cooling systems to go with it. But it’s not just the hardware side of things where we can find trouble. We also need to keep a lookout for all the security breaches that assault companies every day across the globe. All of these can cause problems for your hardware. What happens when you come in one day and your Exchange Server is dead? By dead, we mean one of the following:
- Storage failure
- Hardware failure
- Corruption in the OS
In the list we mentioned storage failures, but you might argue you have never seen this or it’s rare. Well, when you running half a million users on a SAN, your disks go quicker than you think, especially the SSD ones.
Storage does not necessarily need to be your SAN; it can be the DAS (direct-attached storage) where you are running a Raid 1 config or no Raid and it fails. You will need to recover the server. We will look at that a bit later in the article.
Hardware failures can happen out of the box or over a period of time. You can have a Gen5 server, for example, that is still running after seven-plus years but has a Gen10 server that has been replaced a few times.
Or it can be corruption in the operating system. This can happen when a server is not shut down cleanly or it is a virtual server and the storage crashes as mentioned before. When the server starts, your Exchange services don’t want to start up or the operating system Blue Screen of Death and you get that big smiley face to say, “oops we have run into a problem...”
Malicious viruses can trigger issues and be the cause of an operating system in Exchange not booting or files getting deleted. As we all know, there are several ways these viruses can infect your system. They can come from attachments in emails that a user opens or admins plugging infected USB sticks in the servers they manage to copy data. Because these admins usually have elevated access, the virus can do more damage.
So, in whatever situation you are in, what are the options if your Exchange Server is dead? What do you do next? Here are some options.
- AD recovery (if the OS is corrupt or missing).
- Recovery from scratch (if AD is gone and you don’t have backups).
- Recovery from third-party software tools to get access to the database.
- Drive recovery from a vendor if the disks are damaged.
- Conversion of OST files to PST.
Let’s take a look at these in a bit more detail and how to perform them.
Active Directory (AD) recovery
If the operating system is corrupt or not functioning, you can look at doing a recovery. But there are a few things you should try beforehand to see if you can get the operating system functional instead of recovery. They are:
Running an SFC scan using the command:
The above command checks the integrity of the files and tries to repair it.
Sometimes you need to run this in safe mode for it to fix corrupt files. If that option does not work, then you can try option 2:
DISM /Online /Cleanup-Image /RestoreHealth
This command can be extended to include a source if you don’t have one. The above command also tries to repair the operating system. If it does, then you can try Option 1 again to make sure everything is sound.
If the second option fails, then you need to look at doing a recovery. This involves the following:
- Building a new VM.
- Resetting the current computer account.
- Shutting down the old server.
- Joining the new server with the same name and IP to the domain.
- Installing all the prerequisites for Exchange (whichever version you had installed).
- Running Windows updates.
- Installing Exchange using the recovery switch: Setup.exe /IAcceptExchangeServerLicenseTerms /Mode:RecoverServer
- Install any security updates.
- Attach your disks and mount the stores.
Recovery from scratch
Rebuilding from scratch is never a nice task. This means that your backups never worked or you don’t have any backups. This would involve creating a brand-new domain and installing Exchange and everyone will start with a clean mailbox. The business will also be down for a significant time because mail will bounce.
The next point can tie in with the recovering from scratch. You could look at using a third-party tool to access the DB. You might have had a copy of that DB or you can access the data on that disk, whatever the reason, third-party software has come in very handy in some situations. With companies worried about downtime, they are more worried about data loss and want to get the data back. Stellar Data Recovery has been around for many years and has a lot of experience in this field with recovering data from offline EDB files.
If the disk is damaged, maybe due to an air-conditioner leaking and it shorted out the server, but if the disks are OK enough to recover data, you can take it to a vendor that will read the spindles and recover the data for you. This exercise is a rather expensive one, so please take note.
Conversion of OST to PST files
If in the event of complete disaster and no recovery exists, you do still have the OST files from users that you can convert to PST files and import into the new Exchange Server. There may be a chance of small data loss if something is wrong with the OST file or the conversion results in PST files that are very large and difficult to read. This kind of recovery can only be done with third-party software like Stellar Converter for OST.
Your Exchange Server is dead: Long live Exchange Server!
So, hopefully, even after you find out your Exchange Server is dead, you may be able to resuscitate it with one of these options.
Featured image: Shutterstock / TechGenix photo illustration