The output should be like this – dd if=/dev/zero of=/tmp/laptop.bin bs=1G count=1 oflag=directġ073741824 bytes (1.1 GB) copied, 11.5062 s, 93.3 MB/s

Run the following command to test the data without cache - $ dd if=/dev/zero of=/tmp/laptop.bin bs=1G count=1 oflag=direct The output should be like this – sudo hdparm -W0 /dev/sda To deactivate cache, use the following command – $ sudo hdparm -W0 /dev/sda The above command copies 1.1GB of data and 94.0 MB/s is served for the test. Run the following command to test the data with cache- dd if=/dev/zero of=/tmp/laptop.bin bs=1G count=1 oflag=directġ073741824 bytes (1.1 GB) copied, 11.4265 s, 94.0 MB/s Time time dd if=/path/to/bigfile of=/dev/null bs=8k Use DD command on Linux to test read speedīefore testing the first flush caches data, use the following command- $ echo 3 | sudo tee /proc/sys/vm/drop_caches Indicates the synchronization I/O for data. Indicates the number of blocks that you want to use in DD to read the block. Indicates the size of the block that you want DD to use (here I have used 1 GB as a block) Indicates the output file that you want to write using the DD command Of=/tmp/test1.img(of=/path/to/output.file)

Indicates the input file that you want to read using the DD command. Understanding DD CommandĬhunks of DD command should be like this – if=/dev/zero (if=/dev/input.file) Output should be like this- sudo dd if=/dev/zero of=/tmp/test1.img bs=1G count=1 oflag=dsyncġ073741824 bytes (1.1 GB) copied, 11.9635 s, 89.8 note that, 1GB is copied during the test and 89.8 MB/second is served throughout fthe test. Open your Linux root terminal and add the following command- $ sudo dd if=/dev/zero of=/tmp/test1.img bs=1G count=1 oflag=dsync

What is DD Command?ĭD is a command-line utility for Unix and Unix-like operating systems where the primary purpose is to copy a file and converting the format of the data during the process. Do you know how to check the performance of a hard drive like checking the read and write speed on your Linux operating systems? then, this article is for you!! which is basically created to provide you an overview of DD command, which is geared towards better guidance to new users and as an exploration tour for getting started to the Linux world.

Img to dmg using dd