Design and implement caching for disks

Caching plays a crucial role in optimizing disk performance for SAP workloads in the Azure environment. By strategically implementing disk caching, you can significantly improve application response times and reduce latency. In this article, we will explore how to design and implement caching for disks in Azure when planning and administering Azure for SAP Workloads.

Read Caching:

Read caching accelerates the read operations by holding a copy of frequently accessed data in a cache. When a read request is made, Azure checks if the data is available in the cache. If it is, the data is fetched directly from the cache instead of accessing the disk, resulting in faster read times and reduced latency.

To enable read caching for disks in Azure, you need to consider the following:

• Virtual Machine Series: Not all virtual machine series support read caching. Refer to the documentation to determine which series of virtual machines are compatible with read caching.
• VM Size: The size of the virtual machine determines the amount of cache available. Larger VM sizes offer more cache memory, which can result in better performance for read-intensive workloads.
• Operating System: Some operating systems have different default settings for read caching. It is recommended to understand the default settings for the operating system you are using. You can modify the settings if necessary.
• Disk Type: Azure offers different disk types like Standard HDD, Standard SSD, Premium SSD, and Ultra SSD. Not all disk types support read caching, so ensure you choose the appropriate disk type that aligns with your caching requirements.

To enable read caching on a disk, you can use the Azure Portal or Azure CLI commands. Here is an example of using Azure CLI commands to enable read caching on a disk:

az disk update --name --resource-group --caching Read


Write Caching:

Write caching enhances the performance of write operations by temporarily storing the data in a cache before writing it to the underlying disk. This caching method can significantly reduce the latency associated with write operations.

When enabling write caching, it is essential to consider the following factors:

• Data Consistency: Write caching introduces a risk of data loss in case of interruptions like power failures. Therefore, it is recommended to use write caching only when the application can tolerate some data loss or in scenarios where frequent disk writes are not critical to the application.
• Virtual Machine Series: Similar to read caching, not all virtual machine series support write caching. Review the Azure documentation to determine the compatible series for write caching.
• Disk Type: Disk types have different capabilities and support levels for write caching. It is important to select the appropriate disk type based on your workload requirements.

To enable write caching on a disk, you can use the Azure Portal or Azure CLI commands. Here is an example of using Azure CLI commands to enable write caching on a disk:

az disk update --name --resource-group --caching ReadWrite


It is crucial to monitor and optimize the cache usage to achieve the desired performance objectives. Azure provides metrics and diagnostics logs to track cache utilization and identify any potential bottlenecks. You can utilize Azure Monitor and Azure Diagnostics to gather comprehensive insights into cache utilization and performance.

In conclusion, design and implementation of caching for disks in Azure significantly impact the performance of SAP workloads. By understanding the caching types, considering compatibility factors, and utilizing appropriate caching settings, you can optimize disk performance, reduce latency, and enhance application response times.