Flashing or backing up your SD card » History » Version 2
Version 1 (Giulio Moro, 2015-09-25 12:15 AM) → Version 2/9 (Giulio Moro, 2015-09-25 12:34 AM)
h1. Flashing or backing up your SD card
How to do it under MacOs and Linux. For both these tasks you will need the dd program. It comes with many Linux distributions and is available for MacOS.
h2. Backing up your SD card
Put your SD card in the SD card reader. We assume for the rest of this document that your SD card is /dev/mmcblk0
Start by unmounting the SD card in case it is currently mounted:
<pre>
$
sudo umount /dev/mmcblk0
</pre>
In case your partition is smaller than the size of the sd card, you do not need to backup the whole card, so if this is the case, run:
<pre>
$ sudo fdisk -u -l /dev/mmcblk0
</pre>
You might get something along the lines of
<pre>
Device Boot Start End Blocks Id System
/dev/mmcblk0p1 * 63 144584 72261 c W95 FAT32 (LBA)
/dev/mmcblk0p2 144585 3743144 1799280 83 Linux
</pre>
You are interested in the higher value in the "End" column. Pass that value to dd as the count parameter:
<pre>
$ sudo dd conv=sparse count=3743144 if=/dev/mmcblk0 of=bbb_images/your_own_your_precious_backup_image.img
</pre>
How to do it under MacOs and Linux. For both these tasks you will need the dd program. It comes with many Linux distributions and is available for MacOS.
h2. Backing up your SD card
Put your SD card in the SD card reader. We assume for the rest of this document that your SD card is /dev/mmcblk0
Start by unmounting the SD card in case it is currently mounted:
<pre>
$
sudo umount /dev/mmcblk0
</pre>
In case your partition is smaller than the size of the sd card, you do not need to backup the whole card, so if this is the case, run:
<pre>
$ sudo fdisk -u -l /dev/mmcblk0
</pre>
You might get something along the lines of
<pre>
Device Boot Start End Blocks Id System
/dev/mmcblk0p1 * 63 144584 72261 c W95 FAT32 (LBA)
/dev/mmcblk0p2 144585 3743144 1799280 83 Linux
</pre>
You are interested in the higher value in the "End" column. Pass that value to dd as the count parameter:
<pre>
$ sudo dd conv=sparse count=3743144 if=/dev/mmcblk0 of=bbb_images/your_own_your_precious_backup_image.img
</pre>