How to Increase VM Backup Speed

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Backup speed becomes a serious issue when your business operates 24/7 with hundreds of virtual machines up and running. The problem becomes all the more serious when your infrastructure comprises upwards of a thousand VMs. As you scale out, boosting your VMware backup speed becomes a vital element in maintaining your virtual infrastructure’s resilience.

There are many potential factors that could be slowing down your backup processes. Your virtual environment may suffer from insufficient network bandwidth; this could create bottlenecks between the source data storage, the backup software, and/or the destination data storage. The write speed of your target storage could also be limited. These issues relate mostly to resource availability vs. cost, and cannot be easily improved without investment.

There is one major factor that affects backup speed, however: the agility of your backup software.

Modern VM backup solutions can provide you with the maximum possible VM backup speed in a given virtual environment. In this regard, legacy backup solutions leave much to be desired, lagging far behind the ever-growing demands of virtualized environments.

To learn about 21 differences between legacy backup solutions and modern native VM backup solutions, download our free White Paper.

Let’s review some of the features offered by modern VM backup solutions that can help you maximize your VM backup speed. You can download the free trial of NAKIVO Backup & Replication to try these features out for yourself and see the difference.

Full Synthetic Approach to Storing Backups

In contrast to the traditional backup types, such as full, incremental, or differential, the synthetic backup emerged quite recently. With this approach, periodic full backups need not be performed. A full backup is created only once, and all backup jobs thereafter are forever-incremental. Solutions using the full synthetic backup system take advantage of CBT or RCT technologies, which allow the software to quickly identify changed data blocks. Changes are saved to the backup repository as increments, and recovery points are created that reference these changes. Complementary features, such as data deduplication and compression, further reduce the data size, then update recovery point references to the deduplicated data blocks.

The example below illustrates this process, showing how changes (or increments) made over three days in the source VM are then stored in the backup repository.

Synthetic Backup

With the three recovery point references and the changed data blocks recorded in the backup repository, the software can restore the full VM to the Sunday, Monday, or Tuesday state.

Thus, using the full synthetic mode for creating and storing backups drastically reduces the size of the backup jobs. Accordingly, your backup jobs finish much more quickly, as significantly less data needs to be copied.

Elimination of Swap Data from VM Backups

Swap files and partitions are temporary files that are essential for keeping applications running if they need more RAM than is physically available. However, they are unnecessary for recovery purposes. Loading the backup system with processing, transferring, and storing the swap data affects VM backup performance.

The Skip Swap Data feature available in modern VM backup solutions automatically excludes swap files and partitions from your backups. This makes backup jobs smaller and, accordingly, faster.

LAN-free Data Transfer

When VM backup is performed, large amounts of data are transferred through the network, which can affect the speed of both the backup process and business-critical operations. Modern VM backup solutions allow you to optimize your backup traffic. One of the best ways to do this is using LAN-free data transfer, which is based on the Direct SAN Access and Hot Add techniques.

Direct SAN Access mode lets the backup solution read and transfer data over Fiber Channel or iSCSI directly from a SAN storage device. This greatly improves performance for VM backup and replication jobs.

Direct SAN Access

Alternatively, the HotAdd transport mode enables reading VM data directly from VM datastores through the storage I/O stack, bypassing the host’s TCP/IP stack. A snapshot of the source VM is “hot added” as a virtual disk to the VM that runs the backup application. This feature also helps improve backup speed.


Network Acceleration

Reducing the network load can also contribute to VM backup jobs running faster. With the Network Acceleration feature, you can boost the speed of your backup jobs by up to 2X in LAN and WAN networks. This technique is especially useful for remote backup repositories, either offsite or in the cloud.

VM Backup Job Scheduling

Running multiple backup jobs concurrently in large environments can critically slow down your infrastructure performance. The intensive workload stretches your network resources. To avoid overloading your system, you should carefully organize your backup jobs, keeping two aspects in mind:

  • Schedule backup jobs to run at times when the workload on the resources is otherwise minimal. For example, if you have a large environment running transactional applications that are operational 24/7, monitor traffic and choose the time when there is least activity.
  • Select and group your backup jobs carefully, with an aim to keep the time slots for jobs as narrow as possible.

The best backup solutions incorporate convenient and practical tools like NAKIVO Backup & Replication’s Calendar Dashboard for flexible scheduling of your backup jobs.

Creating a NAS-based VM Backup Appliance

One more way to increase VM backup speed is using a NAS-based VM backup appliance. Creating such appliance is as easy as installing a preconfigured VM backup solution on any Network Attached Storage (NAS) device available in your infrastructure.

VM backup appliance based on NAS

This combination of high-performance backup software, hardware, and storage in a single device can help you double your backup speed. You can also benefit from:

  • Up to 5X lower costs compared to purpose-built backup appliances.
  • Reduced backup size owing to the efficient use of techniques such as exclusion of swap files, data deduplication, and data compression.
  • Separation of your VM backups from the rest of your infrastructure, ensuring that you can restore your VMs even if your primary infrastructure is down.
  • Copy of VM backups to the cloud for reliable data protection in accordance with the 3-2-1 backup rule.


Modern VM backup solutions have to provide seamless integration with the rest of the infrastructure while ensuring smooth and well-balanced performance of the whole data protection system. NAKIVO Backup & Replication is an industry leader, offering a full package of VM data protection technologies in a single product. With an outstanding suite of features, NAKIVO Backup & Replication provides robust backup for VMware, AWS EC2 and Hyper-V, as well as replication. The product offers a wealth of functionalities designed to boost your backup performance, including all of those examined in this blog post.

Backup Solution for Hyper-V

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