Symptoms
Customer purchases four SSDs and twenty 600 GB SAS disks and creates a LUN (RAID 10, SAS level). IOmeter (for Linux) is used to test the disk performance. The test shows that the disks' random read (100% read) IOPS is only 260+, far lower than expected 4000.
Cause
IOmeter (for Linux) does not support concurrency. Even though you can set the number of concurrency to 32, the actual number of concurrency is still 1, imposing large pressure on the tool.
Identification Method
1. On the performance monitoring page of the DeviceManager, check the I/O latency. It can be found that the I/O latency is within normal range.
2. Check the I/O latency on IOmeter. It can be found that the latency is as large as 120+ ms, demonstrating that IOmeter (for Linux) does not support concurrency and large pressure is imposed on the tool.
Solution
Advise the customer to use vdbench to test the disk performance.
Application Scope
OceanStor V3 series V300R001
OceanStor V3 series V300R002
OceanStor V3 series V300R003
