my kernel options: ro root=/dev/mapper/vg_nb-lv_root rd_LVM_LV=vg_nb/lv_root rd_NO_LUKS rd_NO_MD rd_NO_DM
You want to use "rd.luks.uuid" kernel option. See "man dracut.kernel".
rd_NO_LUKS (or rd.luks=0) disables LUKS detection entirely. I believe this is not about initrd...
Sorry, I don't understand you. Your request was "don't mount a specific encrypted volume during boot", right?
Actually no. ;-) The question was, if I can force systemd not to mount an encrypted partition. I do not have any other encrypted partitions, so rd.luks=0 is fine.
However, I already found a resolution. "noauto" was missing in /etc/crypttab from some reason. My fault that I haven't double checked. Now it works like a charm.
Thank you Kamil for your answers. :-)
Jan