Introduction to Exchange Server Backup and Recovery
With Exchange Server and any other service, it important to have a good backup and recovery procedure in place to guard the data and recover from any kind of attack or failure. Of course, other things are also vital to keep your Exchange Server healthy, like planned maintenance and updates, security, reliable hardware, enough resources, failover power, and possibly failover features such as Database Availability Groups to reduce downtime and possible data loss. Although you would have all these fail-safe measures in place, there is always a possibility that something happens. You cannot recover from the servers, if you don’t have a reliable backup of your infrastructure.
Why am I saying infrastructure and not Exchange Server, when it comes to backing up the Exchange Server? Well, the reason is that although Exchange Server hosts the email service, it is dependent on other servers to be healthy and to essentially work. The Exchange Server is dependent on the Active Directory server. When you back up the Exchange Server, you need to also back up the Active Directory server. Restoring the Exchange Server alone will not do any good as most of the configurations are stored in the Active Directory schema.
When backing up the Active Directory and the Exchange Server, you must take into consideration the right backup application and its compatibility with the operating system, and the Exchange Server version installed.
1. The Right Application
Being an Exchange Admin, you will always been asked to restore an old email, say from two months ago or even older. This could be an issue if you have retention policies and the email has exceeded those policies. In such a case, the only way to restore the email is from backup. Now, of course, you would need follow a lengthy process to recover just a single email by restoring the entire backup of that date, create a recovery database, and use the New-MailboxExportRequest to export the whole mailbox or date-range to PST.
This process, apart from taking a lot of resources, will take a lot of time. Would that be even feasible for one email? In such cases, it is suggested that you would look for a backup software which can also take a granular backup of the Exchange Server. This way, you can easily restore a particular email from the backup directly to the user’s mailbox.
Firstly, the right choice of backup software is crucial to the business.
After choosing the right software, you can take the backup of Exchange server. There are three types of backup methods:
Full: As it is clear from the name, the ‘Full’ backup is a complete copy of the server, storage, application and files system, and system state. It will have the whole server, including all the data — if it is static data or not. The full backup is a complete copy of the server or data which can be used to restore from any backup copy you took. This method is ideal for small and medium-sized businesses.
Incremental: This is a partial copy of the data or server. An incremental backup will only back up the changes that were made from the last backup run. The first time the backup is taken, a full backup is done but afterwards, only the changes are copied. This will take much less time than the full backup. When restoring, you will need the full backup and the incremental backup till the point you are restoring.
Differential: Differential is quite similar to the Incremental backup. In this, the first time a full backup is taken, then it backs up daily any changes to files from the last full backup. So, to restore a file, you would not need all the incremental backups and the last backup. All you need is just the last full backup.
Another backup method is the file system. However, the file system is not a viable backup solution for Exchange Server. If you would go for backing up your Exchange Server via file system, you might end up with a corrupted mailbox database and possibly you will not be able to restore your server with just the database file.
2. The Backup Medium
There are various medium where you can back up your data. However, you need to make sure that the backup software would need to support the hardware. The mostly used medium are:
Tapes: Tapes come in various types and sizes. The LTO-8, which is the latest, supports up to 30 TB of compressed data in one tape. You can have a daily tape, with also a monthly one. The only downside of this is that the hardware and the tapes are a bit expensive and the tapes can be easily damaged since they are magnetic. Also, you would need to keep the tapes in a fireproof safe outside the office. So, you would need manual intervention from the staff who are managing the backups to keep the tapes safe and taken offsite.
Disks: There are cases where backups are taken either on USB drives or NAS boxes. Although there is no harm in this, there is the issue of hardware. If you are not using SSDs, which would be expensive to buy for daily and monthly, the drives can be easily damaged and security would still be an issue. And NAS boxes cannot be taken offsite. So, if something happens and the server cabinet catches fire or it is flooded, the backup is lost. Apart from those disasters, if your network is attacked by a ransomware, since it is a network storage, it will be infected as well.
Cloud: There are many cloud providers that can offer storage-as-a-service such as Microsoft Azure, Amazon, Google One, and others. The cost of cloud storage is low as compared to the cost of drives and tapes. However, instead of having a capital cost, you will shift on the operational side. It is practical but on a large scale, it would be expensive to keep. The downside of it is that it depends on the internet connection speed to how quickly you can backup and restore your data.
3. The Right Companion Tools
Although the backup and recovery can be done with the right software that can secure your data, there is nothing which covers you if the database gets corrupted or the server gets damaged. Yes, you can always restore from backup, but from the time of the backup to the point in time of the disaster, you will have to accept the data loss. In such cases, you can rely on third-party Exchange Server Recovery applications like Stellar Repair for Exchange which can easily open any version of Exchange Database, corrupted, and export to PST in a granular manner. You can also use the tool to export and import directly to a live Exchange Database and Office 365 tenant.
