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Test disk performance
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Test disk performance

For complete testing of cloud server disk performance (read and write IOPS and throughput), use the fio utility. For testing you can use file tests — prepared text files with test settings.

  1. Install the fio utility.
  2. Prepare the disk for testing.
  3. Test performance.

Test results can be compared to the limits for local disks and network volumes.

Install fio⁠

  1. Connect to server.

  2. Set fio:

    sudo apt update
    sudo apt install fio

Prepare disk⁠

carefully

Do not use this command for disks that contain any information — the command destroys all data on the disk. The examples below show tests with a write to disk with filename=/dev/sdb — the write will also destroy the data and file system on the disk if it is there.

To exclude the influence of services and file system performance on the test result, we recommend create an empty network volume and fill it with data:

dd if=/dev/urandom of=/dev/sdX bs=4M

You can use a file for tests, but the result may not be representative, especially if you are using a root partition.

Test performance⁠

Select a test:

Test Parameters:

  • size — total size of the test file;
  • blocksize — the size of one block with which a read or write operation is performed;
  • filename — file to write or read. The examples below show tests with a write to disk with the filename=/dev/sdb parameter — the write will also destroy the data and file system on the disk, if there is any;
  • iodepth — number of threads.

Random recording in 4KB blocks⁠

  1. Create a test:

    nano write.ini

  2. Add content to the file:

    [writetest]
    size=2000M
    blocksize=4k
    filename=/dev/sdb
    rw=randwrite
    direct=1
    buffered=0
    ioengine=libaio
    iodepth=32

  3. Run the test:

    fio write.ini

    In the test output, look for the IOPS value:

    write: IOPS=118, BW=475KiB/s (487kB/s)(2000MiB/4310296msec); 0 zone resets

Random recording in 4 MB blocks⁠

  1. Create a test:

    nano write.ini

  2. Add content to the file:

    [writetest]
    size=2000M
    blocksize=4M
    filename=/dev/sdb
    rw=randwrite
    direct=1
    buffered=0
    ioengine=libaio
    iodepth=32

  3. Run the test:

    fio write.ini

    In the test output, look at the throughput (BW) value:

    write: IOPS=25, BW=100MiB/s (105MB/s)(2000MiB/19974msec); 0 zone resets

Random read in 4KB blocks⁠

  1. Create a test:

    nano read.ini

  2. Add content to the file:

    [readtest]
    size=2000M
    blocksize=4k
    filename=/dev/sdb
    rw=randread
    direct=1
    buffered=0
    ioengine=libaio
    iodepth=32

  3. Run the test:

    fio read.ini

    In the test output, look for the IOPS value:

    read: IOPS=320, BW=1280KiB/s (1311kB/s)(2000MiB/1599899msec)

Random read in 4 MB blocks⁠

  1. Create a test:

    nano read.ini

  2. Add content to the file:

    [readtest]
    size=2000M
    blocksize=4M
    filename=/dev/sdb
    rw=randread
    direct=1
    buffered=0
    ioengine=libaio
    iodepth=32

  3. Run the test:

    fio read.ini

    In the test output, look at the throughput (BW) value:

    Read: IOPS=25, BW=100MiB/s (105MB/s)(2000MiB/19911msec)