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Information for those wondering what this command does.
sudo: This command is used to run the subsequent command (dd in this case) with superuser (administrative) privileges. It allows the command to access /dev/sda, which is a device file typically representing a disk drive.
dd: This is the command used for copying and converting files or data streams. It is often used for tasks such as creating disk images or copying data between devices.
iflag=direct: This option instructs dd to use direct I/O for data transfer. Direct I/O bypasses the kernel's caching mechanism and may be useful for performance reasons, especially when dealing with large amounts of data.
if=/dev/sda: This specifies the input file (or device) from which dd will read data. /dev/sda typically refers to the first SATA or SCSI disk in a Linux system. Reading from /dev/sda allows dd to read data directly from the disk.
of=/dev/null: This specifies the output file (or device) where dd will write data. /dev/null is a special device in Unix-like operating systems that discards all data written to it. In this command, it's used to discard the data read from /dev/sda, effectively measuring the speed of reading data from the disk without actually storing it anywhere.
count=1: This option specifies how many blocks dd should copy. In this case, count=1 means dd will read and transfer only 1 block of data from /dev/sda to /dev/null. Since /dev/null discards all data written to it, this effectively results in dd reading just one block of data from the beginning of /dev/sda and then stopping.
