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Vdbench

Installing Vdbench

You need to recompile Vdbench source code before executing Vdbench on an ARM-based server.

  1. Download the Vdbench package to the /home directory of each client.

    https://www.oracle.com/webapps/redirect/signon?nexturl=https://download.oracle.com/otn/utilities_drivers/vdbench/vdbench50407.zip

  2. Go to the /home directory of each client and decompress the Vdbench package.
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    cd /home && unzip vdbench50407.zip
  3. Install Java.
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    yum -y install java

    Vdbench depends on Java. If Java has been installed, skip this step.

  4. Check whether Vdbench is running properly.
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    cd vdbench50407
chmod +x vdbench
./vdbench -t

    If "Vdbench execution completed successfully" is displayed, Vdbench is running properly.

Vdbench Test Model

Vdbench runs by executing a workload configuration file. You only need to execute the workload configuration file on any of the clients. The client automatically logs in to other clients based on the IP addresses of other clients specified in the workload configuration file to perform the test. Before the test, create several RBD images and map them to the local RBDs (/dev/rbd0) on the clients. Vdbench performs read and write tests on the RBDs.

Creating a Vdbench Workload

In this example, one Ceph client is used. The client is mapped to three RBDs. The read/write data size of each RBD is 100 GB. Create a 4 KB Vdbench random read workload on any of the clients (for example, client1).

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vi /home/4k_randread.txt

Add the following content:

  1. Set unified default parameters for all test machines. Change the Vdbench path based on site requirements. In this example, the path is /home/vdbench50406. 
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    hd=default,vdbench=/home/vdbench50406,user=root,shell=ssh
  2. Define the test machines. 
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    hd=hd1,system=client1

    Table 1 describes the parameters.

    Table 1 Parameter description

    Parameter

    Description

    hd

    Name of the test machine.

    system

    IP address or name of the host.
  3. Define the storage devices. 
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    sd=sd10,host=hd1,lun=/dev/rbd0,openflags=o_direct,threads=16
sd=sd11,host=hd1,lun=/dev/rbd1,openflags=o_direct,threads=16
sd=sd12,host=hd1,lun=/dev/rbd2,openflags=o_direct,threads=16

    Table 2 describes the parameters.

    Table 2 Parameter description

    Parameter

    Description

    sd

    The storage device name must be globally unique.

    host

    ID of the host where the storage device is located.

    lun

    Raw drive letter or file system name. Vdbench can be used to create a drive. The drive letter in this test is the Ceph RBD/dev/rbd.

    openflags

    Flag used to open a LUN or file. Generally, this parameter is set to o_direct to bypass the cache mechanism and directly write data to drives.

    threads

    Maximum number of concurrent I/O requests to the storage device. The default value is 8 and can be changed as required.
  4. Define the workload. 
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    wd=wd1,sd=sd*,rdpct=100,seekpct=100,xfersize=4k

    Table 3 describes the parameters.

    Table 3 Parameter description

    Parameter

    Description

    wd

    Workload name.

    sd

    ID of the storage device to be used.

    rdpct

    Ratio of read requests to total requests.

    • rdpct=100: All requests are read requests.
    • rdpct=0: All requests are write requests.

    seekpct

    Random seek percentage.

    • seekpct=100: All I/Os are random.
    • seekpct=0: All I/Os are sequential.

    xfersize

    Data block size.
  5. Define the run. 
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    rd=rd1,wd=wd1,iorate=max,elapsed=600,format=restart,maxdata=100G,interval=5,warmup=30

    Table 4 describes the parameters.

    Table 4 Parameter description

    Parameter

    Description

    rd

    Name of the run.

    wd

    ID of the workload.

    iorate

    One or more I/O rates.

    • iorate=100: Run 100 I/Os per second.
    • iorate=(100,200,…): Run 100 I/Os per second, then 200 I/Os per second, and so on.
    • iorate=(100-1000,100): Run 100 I/Os per second, with an increment of 100, until to 1000 I/Os per second.
    • iorate=max: I/Os are delivered to the storage device at the maximum I/O rate that the storage system can bear. If different proportions of I/Os are defined, I/Os are delivered at the maximum rate based on the proportions.

    elapsed

    Running duration, in seconds.

    maxdata

    Maximum capacity.

    interval

    Report interval.

    warmup

    Warm-up duration.

Performing a Vdbench Test

The following uses the 4 KB random read as an example. In other scenarios, adjust the test configuration based on the specific service requirements. (Before performing a read operation, ensure that the block device has data.)

The 4k_randread.txt workload created in Vdbench is used as an example.

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cd /home
/home/vdbench50406/vdbench -f /home/4k_randread.txt -o 4k_randread_output

-f specifies the workload configuration file to be tested. -o specifies the directory for storing test results.

Collecting Test Results

After the test is complete, the test results are exported to the output directory created in the current directory. You can set the -o parameter to change the directory for storing the test results.

For example, in Performing a Vdbench Test, the test results are exported to the /home/4k_randread_output directory.

Check the test results.

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cd /home/4k_randread_output
cat totals.html

The totals.html file contains the following information (i/o rate indicates the IOPS, MB/sec indicates the bandwidth, and resp time indicates the latency).

Parent topic: Test Procedure