Frédéric From France

Please understand me correctly.
I don't see much need to change the installation script.
All other issues are general Linux administration issues and they are very well covered on the Internet.

Hello, Frédéric From France.
There are many questions here.
1) fault tolerance.
2) recovery after exiting the working state of the root file system.
 
(1) CD card, eMMC,  are all flash drives.
Technologically, they are different, but they all have a limited resource for recording.
Armbian tries to reduce the number of write transactions using the overlay file system.
In fact, system write transactions occur in a file located in RAM and are synchronized
with the real file system on the drive at longer intervals than the system ones.
 
(2) You want to place the entire root file system on an LVM partition whose type is linear.
In this case, you have to recreate the initrd to make it work.
And if your drive at the physical level starts to fail or the LVM partition is full, you get very big difficulties for data recovery.
 
packages/bsp/common/usr/sbin/armbian-install
This is a very simple script that makes a copy of the OS on your CD card from which you booted and work on an empty nand, SATA, eMMC or NVME.
 
Your drives are eMMC and NVME.
What would I do at the very beginning of the journey, when both drives are clean?
Boot from the SD card and install the system on eMMC.
Boot from eMMC. (for health check)
Mark up the NVME drive as LVM or as BTRFS. (The BTRFS file system will provide you with all the necessary functionality.)
Make logical partitions for target folders "/opt" "/var" "/srv" "/home".
Boot from the SD card and copy the contents of each target folder to the corresponding logical partition while retaining all rights for files.
Add the necessary mount entries in the /etc/fstab file located on the eMMC.
Boot from eMMC. You are the master of the situation!
 

For separate ext2 boot partition, I think you can pass BOOTFS_TYPE=ext2 to the compile commandline.
 
If you are ok with writing extensions for armbian build framework or to modify the same, the script that handles partitioning is lib/functions/image/partitioning.sh. There are few hook used functions in there. I am not 100% sure if using those in a custom extension will allow to use LVM for partitioning or not, so you have to try that yourself. Worst case scenario, you have to modify partitioning.sh to add support for LVM.

Traditionally I use LVM in our Storage in our servers, and we started doing it on the ARM64 servers too.
 
I am using this with Raspberry PIs and now with Armbian too.
 
I also use cloud-init for server customization, just like ubuntu does with the RPI image now. This is very good, as you can create users, add keys, install packages, set networking... extend partitions, all in an standard way.
 
So, the requirements for my Armbian image are, an extra vfat partition for cloud-init metadata, and the ROOT to be created with LVM instead of just ext4.
 
I managed to implement most with user extensions, except the Dockerfile that required extra packages and configurations, and also I had to patch the partitioning part of the script, in a similar way the CRYPT extension does, as the root filesystem will come from mapper and not from the root device, this is not possible to do from an extension.
 
I have it working for the HC4 in the master branch. I want to port it to the M1 and possibly XU4.
 

Hello Everyone,
As I am still working on hardening my Odroid-M1 servers, I am looking for a solution to activate a real console for root login only. My homelab is not in the same room as my desk, so I need to get access from an internal VLAN with restrictions and take control even if the network drivers are not enabled. Have you tested or used a UART to Ethernet converter like https://www.pusr.com/products/ethernet-to-uart-modules-usr-k7.html
or
https://www.waveshare.com/uart-to-eth.htm
 
or something else?
 
Let me know your thoughts.
 
Sincerely, Frederic