Performance Questions

Last updated: 2019-10-16 20:26:35

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How to measure the performance of a cloud disk?

The following metrics are generally used to describe the performance of a storage device:

  • IOPS: Read/write count per second. IOPS varies by the underlying drive type of the storage device.
  • Throughput: Read/written data volume per second, unit in MB/s.
  • Latency: Time elapsed from sending an I/O operation to receiving an acknowledgement (in seconds).

How to test the disk performance?

We recommend you use FIO to perform pressure testing and verification on the cloud disk. For more information, see Measuring the performance of cloud disks.

Does the I/O size of the application read-write affect the IOPS performance?

Yes. For a given resource, the IOPS you get is determined by the I/O size of the read and write operations of the application. Usually, when reading and writing small blocks (for example, I/O size of 256 KB), the IOPS performance of the disk can be fully used.

Does the I/O size of the application read-write affect the throughput performance?

Yes. For a given resource, the throughput you get is determined by the I/O size of the read and write operations of the application. Usually, when reading and writing large blocks (for example, I/O size of 1MB), the throughput performance of the disk can be fully used.

Can multiple disks be logically combined into one disk to get better performance?

Yes. You can stripe these multiple cloud disks that are mounted to the CVM to balance I/O load to multiple disks, increasing I/O parallel capacity to implement better performance than a single disk. For more information, see Building LVM logical volumes from multiple elastic cloud disks.