I am successfully running a system with several devices, including root, set up on bcache with both backing and cache devices on LVM volumes. Initiramfs scripts are not bright enough to detect this. Details are discussed in bug #1573982. Adding line "vgchange -ay" to /usr/share/initramfs-tools/scripts/local-top/lvm2, as suggested in comment 8 on that bug, works.
I am successfully running a system with several devices, including root, set up on bcache with both backing and cache devices on LVM volumes. Initiramfs scripts are not bright enough to detect this. Details are discussed in bug #1573982. Adding line "vgchange -ay" to /usr/share/ initramfs- tools/scripts/ local-top/ lvm2, as suggested in comment 8 on that bug, works.