CentOS 7 启动出现如下错误not syncing:VFS: Unable to mount root fs on unknown，详见下面附图。原因初步考虑是是更新了内核3.10.0-514.
CentOS 7 启动出现如下错误
not syncing:VFS: Unable to mount root fs on unknown，详见下面附图。原因
初步考虑是是更新了内核3.10.0-514.6.1.el7后出现的问题。处理
- 开机启动时选择旧版本的内核启动
- 成功进入系统后改变开机默认选择的内核
- 查看可选内核
[root[[@lab](https://my.oschina.net/u/166936)]grub2]# cat /boot/grub2/grub.cfg | grep 3.10.0-327.28.3 menuentry 'CentOS Linux (3.10.0-327.28.3.el7.x86_64) 7 (Core)' --class centos --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-3.10.0-123.el7.x86_64-advanced-193aab79-d53d-4f9a-b122-23fde7f637d3' { linux16 /vmlinuz-3.10.0-327.28.3.el7.x86_64 root=/dev/mapper/centos_nic-root ro rd.lvm.lv=centos_nic/root crashkernel=auto vconsole.font=latarcyrheb-sun16 vconsole.keymap=us rd.lvm.lv=centos_nic/swap rhgb quiet LANG=en_US.UTF-8 initrd16 /initramfs-3.10.0-327.28.3.el7.x86_64.img
- 设置默认启动内核
[root@lab grub2]# grub2-set-default 'CentOS Linux (3.10.0-327.28.3.el7.x86_64) 7 (Core)'
- 显示设置默认启动内核
[root[@lab](https://my.oschina.net/u/166936) grub2]# grub2-editenv list saved_entry=CentOS Linux (3.10.0-327.28.3.el7.x86_64) 7 (Core)
end
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