@@ -140,6 +140,7 @@

         - [Photon OS Logs](photon_troubleshoot/photon-os-logs.md)

         - [Troubleshooting Progression](photon_troubleshoot/troubleshooting-progression.md)

     - [Solutions to Common Problems](photon_troubleshoot/solutions-to-common-problems.md)

+        - [Boot in Emergency Mode](photon_troubleshoot/boot-in-emergency-mode.md)

         - [Resetting a Lost Root Password](photon_troubleshoot/resetting-a-lost-root-password.md)

         - [Fixing Permissions on Network Configuration Files](photon_troubleshoot/network-config-files-permissions.md)

         - [Permitting Root Login with SSH](photon_troubleshoot/permitting-root-login-with-ssh.md)

@@ -150,6 +151,7 @@

         - [Installing Tools From Repositories](photon_troubleshoot/installing-tools.md)

         - [Linux Troubleshooting Tools](photon_troubleshoot/linux-troubleshooting-tools.md)

     - [Troubleshooting With systemd](photon_troubleshoot/systemd.md)

+        - [Enabling `systemd` Debug Shell During Boot](photon_troubleshoot/enabling-systemd-debug.md)

         - [Troubleshooting Services with `systemctl`](photon_troubleshoot/troubleshooting-services.md)

         - [Analyzing System Logs with `journalctl`](photon_troubleshoot/analyzing-system-logs-with-journalctl.md)

         - [Inspecting Services with `systemd-analyze`](photon_troubleshoot/inspecting-services-with-systemd-analyze.md)

@@ -11,6 +11,7 @@

         - [Photon OS Logs](photon-os-logs.md)

         - [Troubleshooting Progression](troubleshooting-progression.md)

     -   [Solutions to Common Problems](solutions-to-common-problems.md)

+        - [Boot in Emergency Mode](boot-in-emergency-mode.md)

         - [Resetting a Lost Root Password](resetting-a-lost-root-password.md)

         - [Fixing Permissions on Network Configuration Files](network-config-files-permissions.md)

         - [Permitting Root Login with SSH](permitting-root-login-with-ssh.md)

@@ -21,9 +22,10 @@

         - [Installing Tools From Repositories](installing-tools.md)

         - [Linux Troubleshooting Tools](linux-troubleshooting-tools.md)

     -   [Troubleshooting With systemd](systemd.md)

-        -   [Troubleshooting Services with `systemctl`](troubleshooting-services.md)

-        -   [Analyzing System Logs with `journalctl`](analyzing-system-logs-with-journalctl.md)

-        -   [Inspecting Services with `systemd-analyze`](inspecting-services-with-systemd-analyze.md)

+        - [Enabling `systemd` Debug Shell During Boot](enabling-systemd-debug.md)

+        - [Troubleshooting Services with `systemctl`](troubleshooting-services.md)

+        - [Analyzing System Logs with `journalctl`](analyzing-system-logs-with-journalctl.md)

+        - [Inspecting Services with `systemd-analyze`](inspecting-services-with-systemd-analyze.md)

     -   [Network Troubleshooting](networking.md)

         - [Managing the Network Configuration](managing-the-network-configuration.md)

         - [Inspecting IP Addresses](inspecting-ip-addresses.md)

new file mode 100644

@@ -0,0 +1,23 @@

+# Boot in Emergency Mode

+

+If you encounter problems during normal boot, you can boot in Emergency Mode. 

+

+Perform the following steps to boot in Emergency Mode:

+

+1. Restart the Photon OS machine or the virtual machine running Photon OS. 

+    

+    When the Photon OS splash screen appears, as it restarts, type the letter `e` quickly. 

+

+1. Append `emergency` to the kernel command line. 

+

+1. Press `F10` to proceed with the boot.

+

+1. At the command prompt, provide the root password to log in to Emergency Mode.

+

+    By default, `/` is mounted as read-only. 

+    

+    To make modifications, run the following command to remount with write access:

+    

+    `mount -o remount,rw /`

+

+ 

\ No newline at end of file

new file mode 100644

@@ -0,0 +1,17 @@

+# Enabling `systemd` Debug Shell During Boot

+

+To diagnose `systemd` related boot issues, you can enable early shell access during boot.

+

+Perform the following steps to enable early shell access:

+

+1. Restart the Photon OS machine or the virtual machine running Photon OS. 

+    

+    When the Photon OS splash screen appears, as it restarts, type the letter `e` quickly. 

+

+1. Append `systemd.debug-shell=1` to the kernel command line. 

+

+    Optionally, to change logging level to debug, you can append `systemd.log_level=debug`.

+

+1. Press `F10` to proceed with the boot.

+

+1. Press `Alt+Ctrl+F9` to switch to `tty9` to access the debug shell.

\ No newline at end of file

@@ -2,6 +2,7 @@

 This section describes solutions to problems that you might encounter:

+- [Boot in Emergency Mode](boot-in-emergency-mode.md)

 - [Resetting a Lost Root Password](resetting-a-lost-root-password.md)

 - [Fixing Permissions on Network Configuration Files](network-config-files-permissions.md)

 - [Permitting Root Login with SSH](permitting-root-login-with-ssh.md)

@@ -9,13 +9,12 @@ For example, instead of running the /etc/init.d/ssh script to stop and start the

 	systemctl stop sshd

 	systemctl start sshd

--   [Troubleshooting Services with `systemctl`](troubleshooting-services.md)

--   [Analyzing System Logs with `journalctl`](analyzing-system-logs-with-journalctl.md)

--   [Inspecting Services with `systemd-analyze`](inspecting-services-with-systemd-analyze.md)

+- [Enabling `systemd` Debug Shell During Boot](enabling-systemd-debug.md) 

+- [Troubleshooting Services with `systemctl`](troubleshooting-services.md)

+- [Analyzing System Logs with `journalctl`](analyzing-system-logs-with-journalctl.md)

+- [Inspecting Services with `systemd-analyze`](inspecting-services-with-systemd-analyze.md)

 For an overview of systemd, see [systemd System and Service Manager](https://www.freedesktop.org/wiki/Software/systemd/) and the [man page for systemd](https://www.freedesktop.org/software/systemd/man/systemd.html). The systemd man pages are listed at [https://www.freedesktop.org/software/systemd/man/](https://www.freedesktop.org/software/systemd/man/).

-## 

-###