How to transfer running Debian (Buster) system from uSD to SSD

I am a newbie on Rock4B and not very deep in hardware questions and in setting up Linux systems.

I succeeded to setup a Rock4B with Debian Buster on uSD card and installed some environment to monitor some power consumption and temperatures in our building
in setting up: Apache web server, mariadb, adminer to check/change mariadb tables,
mosquitto broker, grafana to store and display data from my home and graphs, and finally some scripting to read the different inputs and store in mariadb.

Now I have seen that uSD card may not be best or long time logging and I want to change to SSD disk.

Meanwhile I had some time to get some more investigatios on the FAQ pages.
So I changed the text below to my open questions.

As I do not know if all FAQ pages are up to date (no date of last changes)here some questions:

1) concerning Rock4B+ Hardware:
As I see on FAQ pages: It possible to have a SSD on USB port to have the debian system there but I have to have uboot on eMMC module (no SPI on my 4B+).
So I suppose I can flash uboot to emmc according to this page

QUESTION 1)
Where do I find the actual uboot to install on RockPi4b+ ?

QUESTION 2)
After installing uboot to emmc: Is it possible to boot my existing system on uSD card (when no SSD on USB port)?
(As I want to do the preparation in night and my system should proceed to run at daytime to have date in my databease)

2) concerning SSD Hardware:
As I see this FAQ page:

Known working under Linux kernel but not directly in bootloader(uSD/eMMC + NVMe booting)
* Samsung EVO series( M key, NVMe ), work well on ROCK Pi 4, fast speed <-- Warning nvme boot via SPI is not possible (970 EVO Plus)

QUESTION 3)
So I suppose that I can use Samsung 970 Evo Plus MZ-V7S250BW, M.2 2280, M-Key / NVMe, 250GB SSD with this case https://www.ebay.com/itm/194134763059

2) concerning Setup od SSD:

QUESTION 4)
Do i have to setup the SSD from sctarch OR is it possible to transfer the actual system from uSD card to SSD and boot from SSD?
If yes: How to transfer the complete system either with debian on SSD card or with Windows?

Which steps do I have to do for setting up SSD and get the system on?
Can someone give a hint on where to find the info or share a command set to do this (including to get the SSD known in debian and formatting.

Thanks so much for supporting!!!

Klaus

Hi Klaus,

that’s what i’d like to know, too. I’ve a model 4b+ with the M2 Extension Board and have tried different M2.NVMEs with no success.

The support pages you mentioned aren’t very helpful in my opinion especially the second one is completely outdated.

If someone here is listening, i’ll appreciate any help, too.

Kind regards
Holger

Hi Holger,
I had no more time to follow up the topic till last week.
So do you have any more info or hints to setup SSD?

Klaus