Centos uses the dd command to create a USB disk boot disk

Centos uses the dd command to create a USB disk boot disk
Format the USB flash disk first: Use fdisk-l to view the USB flash disk to the mount point, for example,/dev/sdb1. Unmount the USB flash disk and run the format command mkfs. vfat/dev/sdb1.

Then re-mount the USB flash drive to create the boot disk:

# dd if=/ntfs/linux_all/sys/CentOS-7.0-1406-x86_64-DVD.iso of=/dev/sdb

Note that/dev/sdb is not/dev/sdb1 and an error is returned.

In this case, you can re-open a terminal and run the dd command to the user: # while killall-USR1 dd; do sleep 5; done
Then, run the dd command to the terminal to display the burning progress:

3618528 + 0 records in3618528 + 0 records bytes (1.9 GB) copied, 392.471 s, 4.7 MB/s3673141 + 0 records in3673141 + 0 records out1880648192 bytes (1.9 GB) copied, 397.562 s, 4.7 MB/s3726407 + 0 records in3726407 + 0 records out00007920384 bytes (1.9 GB) copied, 402.54 s, 4.7 MB/s3779793 + 0 records indd command: dd is a very useful command in Linux/UNIX. It is used to copy an object with a specified size block and perform the specified conversion at the same time. Parameter 1.if= file name: input file name. The default value is standard input. Specifies the source file. <If = inputfile> 3.ibs= bytes: Read bytes at a time, that is, specify a block size as bytes. Obs = bytes: outputs bytes at a time, that is, specify a block size as bytes. Bs = bytes: set the size of the read/output block to bytes at the same time. 4. cbs = bytes: bytes are converted at a time, that is, the size of the conversion buffer zone is specified. 5. skip = blocks: the blocks are skipped from the beginning of the input file and then copied. 6. seek = blocks: the blocks are skipped from the beginning of the output file and then copied. Note: It is valid only when the output file is a disk or tape, that is, it is backed up to a disk or tape. 7. count = blocks: copy only blocks. The block size is equal to the number of bytes specified by ibs. 8. conv = conversion: Convert the file with the specified parameter. Ascii: Convert ebcdic to asciiebcdic: Convert ascii to ebcdicibm: Convert ascii to alternateebcdicblock: convert each row to the length of cbs. Fill unblock with spaces in the missing part: make the length of each line be cbs, and fill lcase with spaces in the deficiencies: Convert uppercase to lowercase ucase: Convert lowercase to swab: noerror: Do not stop notrunc when an error occurs: Do not trunc: Do not truncate the output file sync: Fill each input block into ibs bytes. fill in the missing part with null (NUL) characters.