we have four P2500 SSD, the size is 480GB. These SSDs are new and don't have any data yet.
I formated it as Xfs, and mount it. But, when I write 1KB data, the latency is about 200ms, the same as 10KB、100KB. But, when I add IO pressure, it is OK.
I test it with dd command.
I use blktrace to analyze the entire IO process, the latency from vfs to driver is OK, and only the latency of disk device is high, anout 200ms.
I can't explain the phenomenon, and I need your help.
Thank you very much for your response.
Thanks for posting in our communities. We understand that you're running custom performance tests on your Intel® SSD Pro 2500, 240GB.
Intel official performance results are measured using 4KB files and are run with http://www.iometer.org/ Iometer*. Please bear in mind that custom performance tests will bear different results not measured by us before. This will also vary depending on system specifications and configurations. You can check the official performance results for Intel SSD Pro 2500 in the https://www.intel.com/content/dam/www/public/us/en/documents/product-specifications/ssd-pro-2500-ser... Product Specification document, section 2.2.
We recommend to run production tests on the drives to confirm if they'll meet your business needs.