Understanding Storage Performance

Posted by arinaliu001 on November 30th, 2018

Excellent performance is an everlasting pursuit for storage system vendors. Vendors use different performance parameters to promote product performance, such as 100% cache hit ratio (maximum IOPS), 256 KB I/O bandwidth, and 100% write latency. All vendors want you to believe that they can provide the highest performance and can easily handle business pressure during peak hours. You may want to know how to identify all-flash arrays that truly have high performance from amongst a huge number of potentially misleading promotions.

SPC, the most commonly used third-party platform for evaluating SAN storage performance

Test standards (especially SPC-1 tests for random IOPS effectiveness) proposed by the Storage Performance Council (SPC) are commonly used as a reference for measuring SAN storage product performance in the industry. Mainstream vendors such as EMC, NetApp, Dell, HPE, HDS, Huawei, IBM, and Fujitsu have participated in SPC tests and used the results to promote their product performance and cost-effective features. This makes SPC-1 a well-known indicator for measuring the performance of products from various brands.

The test specifications of SPC-1 are both strict and fair. Its test program prevents deliberate data value manipulation and its test models are similar to mainstream transaction workloads, meaning SPC-1 can be reliably used as a reference to reflect performance in real-life environments.

Service type: For production services, the SPC provides the SPC-1 benchmark test guide. For data analysis services, the SPC provides the SPC-2 benchmark test guide.

Mixed service workload: In the SPC-1 test, multiple service workloads are used for concurrency testing to verify response times of storage systems in mixed service scenarios. The main indicators include different data types (text, binary, and sparse), different block sizes (8 KB to 128 KB), and different read/write ratios, such as sequential reads and writes or random reads and writes.

SPC-1 testing model

Varying service pressure: The SPC increases and decreases dynamic workload behaviors to test the storage performance of varying service pressure. Specifically, the SPC starts tests from the peak value before gradually decreasing and then increasing service pressure. The SPC then simulates two service peaks as shown in the following figure.

SPEC, the most commonly used third-party platform for evaluating NAS storage performance

Founded in 1988, the Standard Performance Evaluation Corporation (SPEC) is a global and authoritative application performance testing organization, designed to formulate a series of application performance evaluation standards. SPEC is a third-party organization that consists of dozens of prestigious and influential universities, research institutes, and IT enterprises.

SPEC uses the latest SPEC SFS®2014 standard performance evaluation benchmark to test file server throughput and response times, and provides a standard measurement method for comparing the storage performance of devices from different vendors in specific application scenarios. This benchmark uses software to establish swbuild scenarios and tests NAS performance when handling metadata-intensive workloads. NAS products from multiple brands, including Huawei and NetApp, have released the performance evaluation results obtained in this scenario.

flash storage:

https://e.huawei.com/de/products/cloud-computing-dc/storage/all-flash-storage