AlanStudio Linux Tutorial

dd if=ifile of=ofile iflag=direct oflag=direct,dsync status=progress bs=1M
dd if=ifile of=ofile iflag=nocache oflag=nocache,dsync status=progress bs=1M
dd if=/dev/sda of=/mnt/usb/sda.img iflag=direct oflag=direct,dsync status=progress bs=1M

Recommend "dd" command using in lower memory linux.

"direct"
Read and write aligned data without using either the OS's internal buffers or L* caching.

"nocache"
Read unaligned input directly from the device but consume a bit memory (100M+)

[root@linux ~]# dd if="input_file" of="output_file" bs="block_size" count="number"

The syntax of 'dd'

[root@~]# dd if=/dev/sda of=/dev/sdb status=progress

Clone whole HDD from hda to hdb (Same as ghost)

[root@~]# dd if=/dev/sda1 of=/dev/sdb1 status=progress

Clone partition from hda1 to hdbb (Same as ghost)

[root@~]# dd if=/dev/hda of=/tmp/mbr.back bs=512 count=1

Backup MBR (assume first block with 512 bytes per block

[root@~]# dd if=/dev/hda1 of=/mnt/sdc1/hda1.iso

Create image file for hda1 (Remember source partition is not same as destination)

[root@~]# dd if=/dev/zero of=/tmp/test bs=1M count=100

Test the IO write speed using DD

[root@~]# dd if=boot.img of=/dev/fd0 bs=1440k

Make the floppy boot disk using 'boot.img'