In libvirt/kvm when booting with only vdb defined, nothing shows up in /proc/partitions, so this seems like a kvm issue. Booting the second drive as vda (without the first drive), it behaves correctly (just like booting the first drive as vda with vdb).
In libvirt/kvm when booting with only vdb defined, nothing shows up in /proc/partitions, so this seems like a kvm issue. Booting the second drive as vda (without the first drive), it behaves correctly (just like booting the first drive as vda with vdb).