Issue

• Installing a kernel throws grubby fatal error: unable to find a suitable template when /boot has btrfs filesystem.

[root@localhost ~]# grep -v '#' /etc/fstab 
UUID=4336519a-a8fd-4ab2-9160-aec20ed3e068 /                       btrfs   subvol=root     0 0
UUID=8b1f75a9-5fc2-422f-a53e-80a3bd4e7f8e swap                    swap    defaults        0 0
[root@localhost ~]# less /boot/grub2/grub.cfg

menuentry 'Red Hat Enterprise Linux Server (3.10.0-327.el7.x86_64) 7.2 (Maipo)' --class red --class gnu-linux --class gnu --class os --unrestricte
d $menuentry_id_option 'gnulinux-3.10.0-327.el7.x86_64-advanced-4336519a-a8fd-4ab2-9160-aec20ed3e068' {
       .
        linux16 /root/boot/vmlinuz-3.10.0-327.el7.x86_64 root=UUID=4336519a-a8fd-4ab2-9160-aec20ed3e068 ro rootflags=subvol=root crashkernel=auto 
rhgb quiet
        initrd16 /root/boot/initramfs-3.10.0-327.el7.x86_64.img
}
[root@localhost ~]# yum update kernel 
.
  Installing : kernel-3.10.0-514.el7.x86_64                                                                                                   3/7 
grubby fatal error: unable to find a suitable template
  Verifying  : kernel-3.10.0-514.el7.x86_64                                                                                                   
Installed:  kernel.x86_640:3.10.0-514.el7                                                                                                                      Complete!
[root@localhost ~]# grep '^menuentry' /boot/grub2/grub.cfg 
menuentry 'Red Hat Enterprise Linux Server (3.10.0-327.el7.x86_64) 7.2 (Maipo)' --class red --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-3.10.0-327.el7.x86_64-advanced-4336519a-a8fd-4ab2-9160-aec20ed3e068' {
menuentry 'Red Hat Enterprise Linux Server (0-rescue-da29b0a93d48ac4483a32bfcbd8dc095) 7.2 (Maipo)' --class red --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-0-rescue-da29b0a93d48ac4483a32bfcbd8dc095-advanced-4336519a-a8fd-4ab2-9160-aec20ed3e068' {

[root@localhost ~]# rpm -qa kernel
kernel-3.10.0-327.el7.x86_64
kernel-3.10.0-514.el7.x86_64