Centos7 enters Emergency Repair Mode

Centos7 enters Emergency Repair Mode

On the centos7 page, the following error occurs:

Welcome to emergency mode! After logging in, type "journalctl-xb" to view system logs, "systemctl reboot" to reboot, "systemctl default" to try again to boot into default mode.
Give root password for maintenance
(?? Control-D ???) :

Solution:

1. Run runlevel to display unknown

2. Modify the default startup level

   A. Delete: mv/etc/systemd/system/default.tar get. back # rename the file.
   B. Create a soft connection file: ln-sf/lib/systemd/system/multi-user.target/etc/systemd/system/default.tar get
   Or
   Ln-sf/lib/systemd/system/runlevel3.target/etc/systemd/system/default.tar get
   You can also use the systemctl command:
   Systemctl set-default graphical.tar get
   Systemctl isolate multi-user.target

   Error: Error getting authority: error initializing authority: cocould not connect: Resource temporarily unavailable (g-io-Error-quark, 1)

3. View the journalctl-xb log

   An error occurred while mounting the log:

   It can be seen that the Mount problem is that the/home file is not mounted.

4. Edit the automatically mounted file vi/etc/fstab

   Comment out the line of Mount/home (back up first)

   #/Dev/mapper/centos-home/home xfs default 0 0

5. Restart server reboot

6. After the startup is successful, the page is stuck in white bars. You can press esc to view the startup details. It is stuck in/etc/rc. d/rc. local. Restart to enter the single-user mode:

   (1). Select e as the default option when starting the instance.

   (2) Find ro's line

   (3) Change ro to rw init =/sysroot/bin/sh and press ctrl + x to start

   (4) After Entering the single-user page, execute chroot/sysroot to obtain the root permission.

7. After entering the single user mode, edit the rc. local file, comment out the startup items related to/home, and restart the server.

8. After the restart is successful, the system enters the normal mode. You can check the/home mounting problem.

   (1). lvs-a-o + devices view disk details. You can see that the attr parameter of home is not a (activated) inactive.

   (2). lvchange-a y/dev/mapper/centos-home to activate home

   (3) mount home, mount/dev/mapper/centos-home/home

   (4) The mounting is successful, and the comments in fstab and rc. local are modified.

9. Reboot successful, problem solved