Examining the VM Processing Cycle
As data is crucial to any backup application, ensuring optimal data flow efficiency is vital. Veeam Backup & Replication excels in this area by providing comprehensive statistics on data flow, enabling users to identify and address any bottlenecks in the data transmission process. This ensures that resources are utilized efficiently, resulting in seamless, high-performance backup operations.
Veeam Backup & Replication processes VM data in cycles. Every cycle includes some stages:
- Reading VM data blocks from the source
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Processing VM data on the backup proxy/worker
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Transporting data
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Writing data to the target
When one data processing cycle is over, the next cycle begins. VM data, therefore, goes over the “data pipe.”
Performance Bottlenecks
As any backup application handles a significant amount of data, it ensures that the data flow is efficient and that all resources engaged in the backup process are optimally used. Veeam Backup & Replication provides advanced statistics about the data flow efficiency and lets you identify bottlenecks in the data transmission process. Veeam Backup & Replication checks the following points in the data pipe:
- Source: The source disk reader component responsible for retrieving data from the source storage.
- Proxy/Worker: Component responsible for processing VM data.
- Source WAN Accelerator: WAN accelerator deployed on the source site. Used for backup copy and replication jobs working through WAN accelerators.
- Network: The network queue writer component responsible for getting processed VM data from the backup proxy and sending it over the network to the backup repository or another backup proxy.
- Target WAN Accelerator: WAN accelerator deployed on the target site. Used for backup copy and replication jobs working through WAN accelerators.
- Target: The target disk writer component (backup storage or replica datastore).
Veeam evaluates resource usage at these points in percentage, reflecting the time components are engaged during the job. An efficient data flow requires minimal latency and balanced utilization of all elements throughout the data pipe.
Inefficient operation of any component can lead to bottlenecks in the data path, causing specific components to work at total capacity while others are idle, waiting for data transfer. Consequently, the entire data flow may slow down to the speed of the slowest point in the path, prolonging the overall data processing time.
To pinpoint a bottleneck in the data path, Veeam Backup & Replication identifies the component with the highest workload, indicating the one working for the most time during the job. For instance, if a low-speed storage device serves as the backup repository, it may hinder the VM data flow, even if data retrieval from the source site's SAN storage and transfer over a high-speed link are optimal. The backup repository's inability to keep up with the transferred data's rate can result in the repository working at total capacity while other components remain idle. This condition is considered insufficient in terms of Veeam Backup & Replication's analysis.
The job session data displays bottleneck statistics, indicating the data path's weakest component. It's important to note that bottleneck statistics don't necessarily imply issues with the backup infrastructure but rather help identify areas for potential improvement. If you notice lower job performance, you can take corrective actions like limiting the number of concurrent tasks for the backup repository to address the bottleneck and enhance overall efficiency.
Throttling as Bottleneck
Apart from the primary data flow points, Veeam Backup & Replication may also identify throttling as a bottleneck. Throttling can occur in the following scenarios:
- If you limit the read and write data rates for a backup repository, a backup repository may become a bottleneck. Veeam Backup & Replication will report Throttling in the bottleneck statistics.
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If you set up network throttling rules, the network may become a bottleneck. Veeam Backup & Replication will report Throttling in the bottleneck statistics.