Установлено ядро 5.3.9, но CentOS упрямо грузит ядро 3.10.0
Сделано
grub2-set-default 'CentOS Linux (5.3.9-1.el7.elrepo.x86_64) 7 (Core)'
cat /etc/default/grub
GRUB_DEFAULT=saved
grub2-editenv list
saved_entry=CentOS Linux (5.3.9-1.el7.elrepo.x86_64) 7 (Core)
grub2-mkconfig -o /boot/grub2/grub.cfg
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-5.3.9-1.el7.elrepo.x86_64
Found initrd image: /boot/initramfs-5.3.9-1.el7.elrepo.x86_64.img
Found linux image: /boot/vmlinuz-3.10.0-1062.4.1.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-1062.4.1.el7.x86_64.img
Found linux image: /boot/vmlinuz-0-rescue-38017916f03e4d3b918b94899ea3bcc1
Found initrd image: /boot/initramfs-0-rescue-38017916f03e4d3b918b94899ea3bcc1.img
done
uname -r
3.10.0-1062.4.1.el7.x86_64