Centos進入緊急救援模式emergency

1.開機後進入緊急救援模式，出現故障訊息

Entering emergency mode. Exit the shell to continue

Type "journalctl" to view system logs.

You might want to save "run/initramfs/rdsosreport.txt" to a USB stick or /boot

after mounting them and attach it to a bug report.

2.到rdosoreport.txt查看到的故障訊息

3.232016] 11-6-16 kernel: XFS (dm-0): Corruption detected. Unmount and run xfs repair

3.232838] 11-6-16 kernel: XFS (dm-0): failed to locate log tail

3.2328391 11-6-16 kernel: XFS (dm-0): log mount/recovery failed: error -117

3.233970] 11-6-16 mount [7921: mount: /sysroot: mount (2) system call failed: Structure needs cleaning.

3.233136] 11-6-16 kernel: XFS (dm-0): log mount failed

3.查看硬碟id與分區，這裡與上面有看到dm-0故障報錯

exec /sbin/blkid

4.可以查看當前有哪些磁區uuid

ls /dev/disk/by-uuid

5.綜合上述情況，應該是/boot引導故障，我們先使用xfs檢查方式

-n 只檢查不做處理

xfs_repair -n /dev/dm-0 

6.使用xfs_repair 將/boot清空後重新建立

-L 將區域清空重新建立

xfs_repair -L /dev/dm-0 

建立好後就可以正常啟動了，但是要注意這有可能是硬碟準備要故障了，維修好要盡快備份資料，否則後面再故障可能就是讀取不到硬碟了。

##故障時開機到引導模式按下e進入畫面情況