How to improve backup performance

Understanding backup performance

Before diving into the troubleshooting process, it's essential to grasp the key factors influencing backup performance. Several elements contribute to the overall efficiency of backup operations.

Data size. The size and complexity of the data being backed up play a pivotal role in performance. Large datasets, complex file structures, and diverse file types can strain backup systems.

Backup frequency. While doing a full backup every day would be great in theory, there is rarely enough bandwidth to do so. Ideal backup frequency varies greatly, but using full backups over the weekend when there is a bigger backup window is easier and more practical for most organizations. Some businesses use differential backups to reduce the time required to get a copy of all the files that have changed since the last backup.

Network connectivity. The speed and capacity of the network connecting the source systems to the backup target significantly impact performance. Limited bandwidth can lead to delays and bottlenecks. This is especially true where external links to cloud disaster recovery sites are involved.

Scheduling. All modern backup software allows for the scheduling of jobs. This can be a delicate balancing act of starting too early and impacting users versus losing unused time later in the backup period. It can take some tweaking to get right, but it is critical to achieve.

Storage infrastructure. The type and configuration of storage devices, whether it's disk-based, tape or cloud storage, affect backup performance. Disk I/O speeds, storage capacity, and the overall health of storage infrastructure are critical considerations.

Data compression. Uncompressed data can be wasteful. It consumes disk space, and disk space costs money. However, using compression is a double-edged sword. It enables the administrator to fit more information on the disk; this results in less data in transport. But it also has the overhead of compressing the data. Most backup tools support compression, but it can cause performance issues when not used properly.

Deduplication. In a similar vein, data duplication can save serious amounts of disk space. The whole concept is based around the fact that within any installed OS, some files and blocks are identical. Why store hundreds of identical blocks when you can have one block and replace the hundreds of identical copies with pointers to the one saved copy?

Replacing all those duplicate files can save disk space, but at the cost of the computation to work out identical blocks and perform the overhead of creating and managing pointers to the one saved copy.

System resources. The hardware resources allocated to the backup server, such as CPU, RAM and disk speed, impact performance. Overloaded or underpowered hardware can lead to slowdowns.

Troubleshooting backup performance issues

Once backup personnel know what affects performance, the next step is to monitor and troubleshoot any issues that arise. Regularly revisiting and refining backup strategies in alignment with evolving technology trends is key to staying ahead and maintaining top backup performance.

There are two monitoring methods that backup admins can use to check in on the backup infrastructure: performance monitoring and baseline performance analysis.

Performance monitoring tools can help gain insights into the backup system's health. Admins should monitor metrics like CPU usage, memory utilization, network throughput, and storage I/O to identify potential bottlenecks.

Admins can also establish baseline performance metrics during normal operations to understand the typical behavior of the backup system. Deviations from these baselines can highlight potential issues.

Once backup performance issues have been caught and identified, admins can decide on the best method to remedy the situation. Below are some of the primary ways backup admins can fix lagging performance.

Network optimization. Optimize network settings and bandwidth usage. Consider scheduling backups during off-peak hours, implementing network acceleration technologies. This can help ensure that the network infrastructure can handle the load.

Storage infrastructure tuning. Fine-tune storage configurations, such as adjusting RAID settings, optimizing disk I/O and ensuring storage devices are functioning optimally. Regular maintenance, such as disk defragmentation, can also enhance performance.

Backup software configuration. Review and optimize backup software settings. Adjust compression and deduplication settings based on the nature of the data being backed up. Ensure that the software in use is updated to the latest version to benefit from performance improvements.

Parallelization and throttling. Explore parallelization options to allow simultaneous backup of multiple data streams. Implement throttling mechanisms to control the rate of data transfer and prevent resource exhaustion.

Hardware upgrades. Consider hardware upgrades if the backup server is consistently struggling with resource limitations. Upgrading CPU, adding more RAM, or adopting faster storage tools can provide significant performance gains.

Stuart Burns is a virtualization expert at a Fortune 500 company. He specializes in VMware and system integration with additional expertise in disaster recovery and systems management. Burns received vExpert status in 2015.