RPi5 with 4TB NVMe SSD as Storage ?

Just install LE on the SSD like you did on sd-card and boot from SSD without sd-card.

I run all my Pi's from only SSD.

MatteN ,

if he has a NVMe to USB adapter and the luck, that his Luxar NVMe is supported by the RPi5 bootloader too you are more than right.

But that the NVMe is detected by the kernel is unfortunately no guarantee that it boots from.

appliedthinking,

If have such adapter, that would be the easiest way. Depending on your experience with the Linux CLI and your goals there also other possibilities with dd and so on.

Do you want remove the SD card and use the NVMe as boot device or only for /storage ?

Because your kernel was already able to find the NVMe the line dtparam=nvme could be obsolete. The dtparam=pciex1_gen=3 is only to force PCIe bus to higher speed level. This speed is not official supported and can make additional trouble. My recommendation: activate these settings as the last step after all other things are ready and observe your dmesg log for sporadic PCIe error messages, to be safe and prevent data corruption.

https://wiki.libreelec.tv/configuration/config_txt

If the OP doesn't have a USB nvME interface then presumably you could boot into Raspberry OS from a uSD card or USB stick and then write the LibreElec image to the PCI-E connected NVMe drive from within Raspberry Pi OS assuming the Raspberry Pi OS 'sees' it. Once you make sure the EPROM bootloader has the PCI-E NVMe as a boot option you can then reboot to LE without the uSD or USB device installed on the Pi?

I've not use LibreElec on a PCI-E NVMe Pi 5 - but that's how I installed Raspberry Pi OS and Ubuntu on two different Pi 5s with NVMe HATs.