I’m trying to install and configure grub.
/dev/sda1 / btrfs rw,relatime,space_cache,subvolid=5,subvol=/ 0
# /dev/sda2
UUID=17C8-E648 /boot vfat rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0
$ grub-install --force --target=i386-pc --recheck --boot-directory=/boot /dev/sda
Installing for i386-pc platform.
Installation finished. No error reported.
$ grub-mkconfig -o /boot/grub/grub.cfg
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-4.14-x86_64
Found initrd image: /boot/initramfs-4.14-x86_64.img
grub-probe: error: unknown filesystem.
Found initrd fallback image: /boot/initramfs-4.14-x86_64-fallback.img
Warning: os-prober will not be executed to detect other bootable partitions.
Systems on them will not be added to the GRUB boot configuration.
Check GRUB_DISABLE_OS_PROBER documentation entry.