ROM Hack How to make a complete backup of your SD card with dual sysnand/emunand

[Chrisssj2]

Im not sure how it works or if its needed
So i have a sysnand and and emunand luma dualboot.
256 GB sd card. one partition is 237 GB Other is not acccesible via windows explorer says i need for format it. (guessing thats emunand)

Now i want to make total backup of SD/3ds but i dunno if the 237 GB backup of the partition I can see of the SD, is really a "total" backup?
The other partition looks empty but i dont know if there is actual data stored there
i dunno
since i already have a 237GB partition how big could it be?

Or is that the part were purely the emunand OS files are stored, and the actual games that are installed on emunand/sysnand are stored on the partition I can see?
(somehow I have it in my mind that emunand stores the games in one partition while sysnand stores it in the next)
But that doesnt seem to make sense since the partition is 237 GB. And I surely have over 10 GB on emunand.. so that wouldnt fit my SD then by that logic...

When you either select A. boot into sysnand it loads one partition or B. emunand loads the other..?


Also if
If I try to make backup of sysnand and emunand with Godmode9
It will say Failed
@ emunand
But it will create a sysnand backup fine
I guess for total backup you should redo the emunand/sysnand backup if you have lets say installed lots new apps since the last backup?

EDIT:
If I try to make backup of sysnand and emunand with Godmode9It will say Failed@ emunand
But it will create a sysnand backup fine

 

[0x40]

If you want to backup the entire SD card, including the partition table and all the unallocated space, install the Windows port of dd from here and run this:

dd id=d: of=backup.img bs=1M --progress

Replace d: with the device letter of the SD card partition.

 

[Chrisssj2]

If you want to backup the entire SD card, including the partition table and all the unallocated space, install the Windows port of dd from here and run this:

dd id=d: of=backup.img bs=1M --progress

Replace d: with the device letter of the SD card partition.

Thanks for providing such solution.(prefer to backup though where i can copy individual files directly, but an entire image is cool)
What about the questions in my OP, id like to understand how this is all stored.
Also It seems I cannot create a backup for my emunand for some reason. But I made one in the past, so whats up.

 

[Deleted member 373223]

An emunand is not 10+ GBs. So it's likely you DO NOT have an emunand

 

[Chrisssj2]

An emunand is not 10+ GBs. So it's likely you DO NOT have an emunand

I do have an emunand. I can boot into either fine.
Sysnand has about 299 titles.
While the emunand has about 40 or so.

 

[Chrisssj2]

Tried using this: https://gbatemp.net/threads/release-3ds-multi-emunand-creator.381603/
But extract nand isn't available for my sd for any nand NR...

Windows disk management shows 1.21 GB healthy partition for the "unaccesible drive" of my sd that asks for format. Which should be my emunand.