sudo grub2-mkconfig -o /boot/grub2/grub.cfg

[user@localhost ~]$ sudo grub2-mkconfig -o /boot/grub2/grub.cfg
Generating grub configuration file ...
device-mapper: remove ioctl on osprober-linux-sda4  failed: Device or resource busy
Command failed.
Found Windows Recovery Environment on /dev/sda6
Found CentOS Linux 7 (Core) on /dev/mapper/centos-root
done

[ag@localhost ~]$ lsblk
NAME                    MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda                       8:0    0 465.8G  0 disk
├─sda1                    8:1    0   260M  0 part
├─sda2                    8:2    0   128M  0 part
├─sda3                    8:3    0 155.5G  0 part
├─sda4                    8:4    0  44.5G  0 part
│ └─osprober-linux-sda4 253:6    0  44.5G  1 dm
├─sda5                    8:5    0   3.9G  0 part
├─sda6                    8:6    0    21G  0 part
├─sda7                    8:7    0   476M  0 part
├─sda8                    8:8    0   488M  0 part
├─sda9                    8:9    0  55.9G  0 part
│ ├─centos-swap         253:1    0   8.6G  0 lvm
│ └─centos-root         253:5    0  47.3G  0 lvm
├─sda10                   8:10   0     2M  0 part
├─sda11                   8:11   0   476M  0 part /boot
└─sda12                   8:12   0  74.5G  0 part
  ├─fedora-root         253:0    0  18.6G  0 lvm  /
  ├─fedora-swap         253:2    0   3.7G  0 lvm  [SWAP]
  ├─fedora-home         253:3    0  46.6G  0 lvm  /home
  └─fedora-tmp          253:4    0   4.7G  0 lvm  /tmp