1) Basically every hardware RAID card comes with another kind of interface?
I guess, yes. It is same as BIOS/UEFI motherboard setups.
I think the steps are the same.
https://www.thomas-krenn.com/en/wiki..._RAID_via_BIOS
https://www.thomas-krenn.com/en/wiki...AID_Controller
2) Is there any card/interface you would recommend?
I'm using a Adaptec controller with arcconf for managing and (manual) monitoring after boot.
For LSI/Broadcom you have storcli.
It has been a while since i used the menu for both. Either would do the job and i don't know any other brands except server vendors as HPE, Dell etc.
It might be possible to read smart data via the smartctl. I need to try again if i can get it working for my Adaptec card.
https://www.thomas-krenn.com/en/wiki...f_CLI_Commands
https://www.thomas-krenn.com/en/wiki/StorCLI_commands
https://unix.stackexchange.com/quest...aid-controller
https://docs.hetzner.com/robot/dedic...id-controller/
3) And do I need to reinstall Linux, or could I just say to the RAID card "Hey, I want RAID 1, start with that disc and mirror it for a while like rsync"?
I think it is basically like formatting a new disk.
You can clone from your original disk to your new virtual disk.
The raid card will keep both disks (under the virtual disk) in sync.