CentOS uses dd commands 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:
[Python] view plaincopy
- # Ddif =/ntfs/linux_all/sys/CentOS-7.0-1406-x86_64-DVD.isoof =/dev/sdb
Note that/dev/sdb is not/dev/sdb1. the following error occurs: isolinux. bin missing or upt.
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
In this case, run the dd command to the terminal to display the burning progress: [python] view plaincopy
- 3618528 + 0 recordsin
- 3618528 + 0 recordsout
- 1852686336 bytes (1.9 GB) copied, 392.471 s, 4.7 MB/s
- 3673141 + 0 recordsin
- 3673141 + 0 recordsout
- 1880648192 bytes (1.9 GB) copied, 397.562 s, 4.7 MB/s
- 3726407 + 0 recordsin
- 3726407 + 0 recordsout
- 1907920384 bytes (1.9 GB) copied, 402.54 s, 4.7 MB/s
- 3779793 + 0 recordsin
Dd 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.
Parameters
1. if = File Name: Enter the 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 the size of a block to 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 ascii
Ebcdic: Convert ascii to ebcdic
Ibm: Convert ascii to alternateebcdic
Block: converts each row to the length of cbs. spaces are used to fill the remaining parts.
Unblock: the length of each row is cbs, and the remaining part is filled with spaces.
Lcase: converts uppercase to lowercase.
Ucase: converts lowercase to uppercase.
Swab: swap each pair of input bytes
Noerror: Do not stop when an error occurs
Notrunc: the output file is not truncated.
Sync: Fill each input block into ibs bytes, and fill the remaining part with null (NUL) characters.
Use wodim to burn a disc: view the optical drive information:
[Python] view plaincopy
- Wodim -- devices
- Wodim: Overviewofaccessibledrives (1 found ):
- -------------------------------------------------------------------------
- 0dev = '/dev/cd0' rwrw --: 'hl-DT-ST' 'dvdramgt31n'
- -------------------------------------------------------------------------
Run [python] view plaincopy
- Wodim-sao-vspeed = 1dev =/dev/dx0/ntfs/linux_all/sys/CentOS-7.0-1406-x86_64-DVD.iso
-V verbose
-After an eject is finished, the disc is automatically displayed.
Speed = 1 dev =, 0: 1 m speed burn to dev =/dev/cd0
