Backup the EMMC

[Der Geist der Maschine]

On my windows PC's I use a program called Macrium Reflect - it takes shadow copies of a hard drive, only saving "active sectors" and applies some compression before saving to an external hard drive. The file it saves is later accessible for individual file retrieval or can rebuild a complete new drive from the saved image.

Is there anything vaguely like that in "ARM" land?

Doesn't my posting come pretty close to that?

• writing and deleting zeros onto the filesystem makes it highly compressable ... just like "saving active sectors"
  
• you can loopback mount the dd'ed image (it might require some tricks to work around the gziped part and so you may want to temporarily gunzip it before loopback mounting) and extract files.