今天早上发现vps莫名其妙无法启动了 报错如下一看就是虚拟文件系统咋啦

Kernal Panic - Not syncing : VFS: unable to mount root fs on unknown-block (0,0)

这种情况换一个内核就可以解决在启动的时候手速快换一个内核就行了不过侧面说明系统自带的内核才是最稳定的 这个问题貌似是虚拟化的驱动没启动导致文件系统找不到

如果没有可用的内核可以试试进入救援模式然后chroot过去安装一个内核

我是换了默认的启动内核引导为grub2
查看系统几个内核

[root@vultr ~]# cat /boot/grub2/grub.cfg |grep menuentry
if [ x"${feature_menuentry_id}" = xy ]; then
  menuentry_id_option="--id"
  menuentry_id_option=""
export menuentry_id_option
menuentry 'CentOS Linux (3.10.0-1160.41.1.el7.x86_64) 7 (Core)' --class centos --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-3.10.0-1160.41.1.el7.x86_64-advanced-14df8438-6b4d-410a-a6b6-cb7b5cfba22c' {
menuentry 'CentOS Linux (3.10.0-1160.15.2.el7.x86_64) 7 (Core)' --class centos --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-3.10.0-1160.15.2.el7.x86_64-advanced-14df8438-6b4d-410a-a6b6-cb7b5cfba22c' {
menuentry 'CentOS Linux (3.10.0-1160.el7.x86_64) 7 (Core)' --class centos --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-3.10.0-1160.el7.x86_64-advanced-14df8438-6b4d-410a-a6b6-cb7b5cfba22c' {
menuentry 'CentOS Linux (0-rescue-dbd8b0cf31a54745ab6828dace4a6da2) 7 (Core)' --class centos --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-0-rescue-dbd8b0cf31a54745ab6828dace4a6da2-advanced-14df8438-6b4d-410a-a6b6-cb7b5cfba22c' {

设置默认启动内核

[root@vultr ~]# grub2-set-default "CentOS Linux (3.10.0-327.el7.x86_64) 7 (Core)"
````
查看现在的默认启动内核

[root@vultr ~]# grub2-editenv list
saved_entry=CentOS Linux (3.10.0-327.el7.x86_64) 7 (Core)