[Solved] Clone SD card with correct size

tinue

I can easily clone an SD card to a file with "dd" on my Mac. I can also add "count" to limit the number of sectors that are read from the SD card.

What I can't figure out is how to find the exact number of sectors that I have to read, in order to back up the entire file system, but not more. How do you create the image file that is being distributed?

tschinz

You don't....

you make a copy of your SD Card partition. The data can sit anywhere within this partition. You shouldn't just copy a part of the partition you will miss some data or corupt the partition. This means if you SD card has a 16Gb partition your image will be 16Gb. You can compress it afterwards if needed.

To create the img file just dd the SD Card

dd if=/dev/sdb of=~/myimage.img

Note you probably want to adapt the input location

Cheers

tinue

I have some SD card images downloaded to my disk: Runeaudio, Raspbian, Cupcade, Hifiberry Testimage, OpenElec, ...

None of these images seem to have the exact size of an SD card, be it 2, 4 or 8GB. So I wonder how all of these images have been made. A simple "dd" from the SD card would result in a dump of exactly card size.

Also it looks like the images are from the entire card, and nor just from one partition: When the image file is "dd"ed back to an SD card, it usually results in more than one partition.

It does look like there are additional tricks available

hamdi

you can use Disk Utility is the best way to cone the SD card with correct size

tinue

The MacOS Disk Utility? It does not know about the ext3 filesystem, and thus can't tell me anything about the partition.
The attached picture is from a Raspbian SD card, but Runeaudio also uses ext3, so I don't think it looks much different there.

Or am I misunderstanding you?

Thanks! Martin

: Bildschirmfoto 2015-05-02 um 21.08.58.png (62.11 KiB) Viewed 4848 times

hondagx35

Hi Martin,

None of these images seem to have the exact size of an SD card, be it 2, 4 or 8GB. So I wonder how all of these images have been made.

The problem is, that there are NO two SD cards with the same size, unless they come from the same manufacturer, same brand and from the same production batch and are brand new.
So as a distributor you always have to make the images a bit smaller to guarantee that they fit on all brands of sd cards.

How do you create the image file that is being distributed?

I make the images on my Linux (Ubuntu) machine using GParted, fdisk and truncate as described here.

Frank

tinue

Hello Frank

Thank you very much for the link. This is exactly the information that I was looking for.

Regards, Martin

preetyjess01

Hey Buddy,

Look this, clone raspberry pi sd card. Here is, you get the best solutions about the SD card clone. I also had similar problem regarding how to clone a raspberry pi sd card, but after this, I solved my all problems. You should to try this once. surely you get best solution from this. And it helps you a lot. I tried this. Thanks.