[CentOS] imaging a drive with dd

Fri Mar 3 02:14:06 UTC 2017
Robert Moskowitz <rgm at htt-consult.com>


On 03/02/2017 09:06 PM, fred roller wrote:
> On Thu, Mar 2, 2017 at 8:36 PM, Robert Moskowitz <rgm at htt-consult.com>
> wrote:
>
>> dd if=/dev/sdb of=os.img bs=1M count=3210
>>
> I would recommend bs=512 to keep the block sizes the same though not a huge
> diff just seems to be happier for some reason and add status=progress if
> you would like to monitor how it is doing.  Seems the command you have
> should work otherwise.

So, given the fdisk output,

Disk /dev/sdb: 111.8 GiB, 120034124288 bytes, 234441649 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x0000c89d

Device     Boot   Start     End Sectors  Size Id Type
/dev/sdb1          2048 1026047 1024000  500M 83 Linux
/dev/sdb2       1026048 2074623 1048576  512M 82 Linux swap / Solaris
/dev/sdb3       2074624 6268927 4194304    2G 83 Linux


would

count=6268927

?

oh, and this way, I can lay the image down on any drive.  Even a mSD 
card (as that is the actual boot device, but the Cubie uboot (and 
linksprite) can run almost completely from a sata drive).

thanks