我的电脑从 Fedora 28 用网络升级 到 Fedora 30.
但 grub2 在开机过程的选单上还是都是 Fedora 28 的选项。
我用的不同指令查询目前电脑的 Fedora 版本，却得到不同结果。
(1) uname -mrs
出现结果是 Linux 5.0.16-100.fc28.x86_64 x86_64
(2) cat /etc/os-release
出现结果是
NAME=Fedora
VERSION="30 (Workstation Edition)"
ID=fedora
VERSION_ID=30
VERSION_CODENAME=""
PLATFORM_ID="platform:f30"
......
(3) hostnamectl
出现结果是
Static hostname: localhost.localdomain
Icon name: computer-desktop
Chassis: desktop
Machine ID: 39247b332bd846d087f072d9763b410d
Boot ID: a5d03a7ad2a9498798f630c296f800f6
Operating System: Fedora 30 (Workstation Edition)
CPE OS Name: cpe:/o:fedoraproject:fedora:30
Kernel: Linux 5.0.16-100.fc28.x86_64
Architecture: x86-64
(4) lsb_release -a
LSB Version: :core-4.1-amd64:core-4.1-noarch
Distributor ID: Fedora
Description: Fedora release 30 (Thirty)
Release: 30
Codename: Thirty