[linux] linux uses dd command to make hard disk image

Production environment

System: linux

Make

1. Use the lsblkcommand to view the serial number of the hard disk mirrored

lsblk

2. Make a hard disk image

sudo dd bs=512 count=117229568 if=/dev/sdc | gzip -9 > image-os.gz

Description ::
countThe size of the hard disk to be mirrored needs to be calculated according to the size of the hard disk
bs: the size of a write block
sdc: the serial number of the hard disk to be mirrored, check the hard disk according to lsblk to modify this

Image compression split and decompression merge

1. Compression and splitting
   The image obtained by dd is generally relatively large and cannot be stored on the CD. The image can be split by the following command, and the split image file can be obtained in the current directory

mkdir image
mv image-os.gz image
tar cjf - image |split -b 3800m - image-os.tar.bz2.

Description ::
-bSplit by file size

2. Unzip and merge
   execute the following command in the directory where the image file is located, you can get the unzipped and merged image file in the current directory

cat  image-os.tar.bz2.a* |tar xj

Mirror installation

1. Use the lsblkcommand to view the hard disk serial number of the installed image

lsblk

2. Mirror installation

gzip -c -d image-os-os.gz | sudo dd of=/dev/sdc

sdc: The serial number of the hard disk to be installed mirrored, according to lsblk to view the hard disk to modify this