Files are often stored multiple times, unnecessarily hogging storage space on data carriers and in backups; therefore, data deduplication is particularly useful for file servers. Virtual desktop infrastructure (VDI) environments also benefit from this technology, for which data deduplication even offers separate options that I also cover in this article. The technology can use both physical data carriers and virtual disks, which means that deduplication can be used effectively in virtual environments.

Once the feature has been installed, the connected hard drives are checked according to a schedule, and the deduplication rate is displayed in the Server Manager console. In this way, you can keep an eye on the success and utility value of deduplication for individual disks. Because you are not forced to deduplicate every single data carrier on a server, you can flexibly control which data carriers are worth the overhead. If you discover that deduplication does not deliver meaningful results for individual data carriers, you can remove them from the configuration at any time. Starting with Windows Server 2019, deduplication not only supports NTFS, but also the Protogon resilient filesystem (ReFS), and therefore very large data carriers, as well.

All told, data deduplication on Windows Server 2022 is a powerful way to optimize storage capacities and reduce costs. However, you need to find a balance between the benefits and the potential challenges to ensure smooth and efficient system management. In this article, I shed light on the technical background of deduplication and show you how to set up and manage data deduplication in a graphical interface, with PowerShell, and from the command line on Windows Server 2022.

The Downside

Of course, you also need to consider the potential downsides of data deduplication because it is not useful in all environments. Database servers, Exchange, or Hyper-V hosts will rarely benefit, although VDI environments are an exception. On virtual machines (VMs), in contrast, deduplication can certainly offer benefits, depending on the server role. Virtual file servers benefit from data deduplication just as much as physical file servers. One possible disadvantage is that data deduplication requires compute resources, which can affect performance on servers that are already heavily utilized. Initializing the deduplication process in particular may involve heavy use of CPU and memory.

Moreover, it is important to configure deduplication carefully to make sure important files are not excluded or inadvertently modified. Another aspect to keep in mind is the dependency of data recovery on deduplication. Because deduplicated data is stored once only, recovery can be more complex than with conventional methods, which entails careful planning and regular testing of backup and recovery processes.

When Not To Dedup

After you decide to use data deduplication on Windows Server 2022, you need to remember that this technology is not the answer for some data types and files. In fact, some data types will benefit less or not at all from deduplication. Formats such as JPEG, MP3, MP4, or ZIP, which already use forms of data compression, offer little leverage for reducing redundancy and saving storage space.

Active database files, especially files that require frequent write operations, are generally not a good choice for deduplication. Constant changes to them can affect deduplication efficiency and, in some cases, performance. Files that are updated in real time, such as system logs, can even be blocked by the deduplication process. Constant write access to these files conflicts with the way deduplication works.

Deduplication is more suited to static data or content that is not frequently modified. Also, where files are individually encrypted, each file is unique, even if the original unencrypted content was identical. This characteristic considerably limits the effectiveness of deduplication, because no significant redundancies can be identified.

Data deduplication is also possible in storage pools and on virtual hard drives. If you have installed role services, a window will appear when you create a new volume. You can use it to enable deduplication for the current volume, assuming deduplication will work on it. It does not matter whether you use data deduplication for data on normal volumes or on virtual disks in storage pools.

SSD, HDD, and NVMe

When implementing data deduplication in environments that use different storage technologies (e.g., hard disk (HDD), solid-state (SSD), and non-volatile memory (i.e., NVMe) drives), you need to consider several aspects. Data deduplication performance can vary greatly depending on your choice of storage technology. HDDs with their slower access times could lead to bottlenecks in deduplication-intensive scenarios, whereas SSDs and NVMe drives, with their higher speed and lower latency, are better suited in this scenario, particularly because deduplication involves many I/O operations that run more efficiently on SSDs and NVMe drives.

The effect of deduplication on the service life of SSDs and NVMe drives is another important aspect. Because the number of write cycles is limited for these storage types, the frequent write activity associated with deduplication could potentially curtail the service life of these devices. You need to take this into account when planning the storage infrastructure and its maintenance cycles.

In environments with a combination of storage types, it might make sense to store deduplicated data on SSDs or NVMe drives to take advantage of the higher speed, while storing larger and less frequently accessed data on the less expensive HDDs. In this way, the storage space on the more expensive SSDs and NVMe drives can be better utilized through the efficient use of data deduplication. Regardless of the type of storage used, it is crucial to implement robust backup and recovery strategies. Deduplication can increase the complexity of data recovery, requiring careful planning and regular reviews of the backup strategies.