Storage I/O performance, also known as storage read/write performance, is the performance that is implemented when disks are attached to different ECS instance types. Metrics of storage I/O performance include IOPS and throughput.
I/O (inputs/outputs or reads/writes) are random or sequential data requests initiated by an application. The volume of I/O requests is also known as the I/O size in KiB, such as 4 KiB, 256 KiB, and 1,024 KiB.
- If the application, such as offline analysis and data warehousing, requires a large amount of I/O, we recommend that you select the big data instance families with higher throughput.
- If the application requires low-latency, random, and small-sized I/O, such as OLTP databases and enterprise-grade applications like SAP, we recommend that you select enhanced SSDs and standard SSDs with high IOPS.
Storage I/O performance of instances
The new generation of enterprise-grade instance families for Alibaba Cloud elastic compute features storage I/O performance isolation. Dedicated storage bandwidths are assigned to ECS instances and disks to avoid the storage I/O preemption among ECS instances. The new generation of enterprise-grade instance families ensures consistent storage I/O performance of applications even during peak hours.
- Large and medium-sized database loads, such as Oracle, MySQL, SQL Server, PostgreSQL, Cassandra, and MongoDB databases.
- Enterprise-grade applications, such as ERP and CRM.
Relationship between instance types and storage I/O performance
The storage I/O performance of an ECS instance varies with instance families and disk-attached instance types. The storage I/O performance of an instance depends on the instance type. A higher instance type provides higher storage I/O performance (IOPS and throughput).
- Scenario 1: If the total storage performance of the attached disks exceeds the maximum storage I/O performance that the instance type can deliver, the final storage I/O performance of the instance is limited to the maximum storage I/O performance of that instance type.
- Scenario 2: If the total storage performance of the attached disks does not exceed the maximum storage I/O performance that the instance type can deliver, the final storage I/O performance of the instance is limited to the maximum storage I/O performance of the disks.
For example, the ecs.g6.8xlarge instance type features 60,000 IOPS. If a 1,600 GiB enhanced SSD PL2 is attached to an instance of the instance type and the IOPS of the enhanced SSD PL2 is 81,800, the maximum storage IOPS of the instance is 60,000 instead of 81,800. For information about the performance levels of enhanced SSDs, see Enhanced SSDs.
After you understand the relationship between instance storage performance and disk storage performance, you can choose instance types and Block Storage devices based on the performance data of instances and disks that meets your business needs. This prevents performance bottlenecks caused by using improper configurations.
Storage I/O performance of new generation of enterprise-grade instance families
The following table lists the storage I/O performance of the new generation of enterprise-grade instance families. For information about other metrics of the instance families, see Instance families.
|Instance type||Maximum IOPS (K, 4 KiB I/O)||Maximum storage bandwidth (Gbit/s)||Maximum throughput (MB/s, 1,024 KiB I/O)|