bcdedit /ems {current} on
bcdedit /emssettings EMSPORT:1 EMSBAUDRATE:115200
bcdedit /store <mountedvolume>bootbcd /ems {default} on
bcdedit /store <mountedvolume>bootbcd /emssettings EMSPORT:1 EMSBAUDRATE:115200
bcdedit /set {bootmgr} displaybootmenu yes
bcdedit /set {bootmgr} timeout 10
bcdedit /set {bootmgr} bootems yes
cmd
to create a channel that has a CMD instance.ch -si 1
or press <esc>+<tab>
shortcut keys to switch to the channel that's running the CMD instance.PowerShell
in the CMD instance, and then press Enter.Scenario | Actions in the serial console |
---|---|
Incorrect firewall rules | Access serial console and fix Windows firewall rules. |
Filesystem corruption/check | Access the serial console and recover the filesystem. |
RDP configuration issues | Access the serial console and change the settings. For more information, see the RDP documentation. |
Network lock down system | Access the serial console from the Azure portal to manage the system. Some network commands are listed in Windows commands: CMD and PowerShell. |
Interacting with bootloader | Access BCD through the serial console. For information, see Enable the Windows boot menu in the serial console. |
Issue | Mitigation |
---|---|
Pressing Enter after the connection banner does not cause a sign-in prompt to be displayed. | For more information, see Hitting enter does nothing. This error can occur if you're running a custom VM, hardened appliance, or boot config that causes Windows to fail to properly connect to the serial port. This error will also occur if you're running a Windows 10 VM, because only Windows Server VMs are configured to have EMS enabled. |
Only health information is shown when connecting to a Windows VM | This error occurs if the Special Administration Console has not been enabled for your Windows image. See Enable the serial console in custom or older images for instructions on how to manually enable SAC on your Windows VM. For more information, see Windows health signals. |
Unable to type at SAC prompt if kernel debugging is enabled. | RDP to VM and run bcdedit /debug {current} off from an elevated command prompt. If you can't RDP, you can instead attach the OS disk to another Azure VM and modify it while attached as a data disk by running bcdedit /store <drive letter of data disk>:bootbcd /debug <identifier> off , then swapping the disk back. |
Pasting into PowerShell in SAC results in a third character if the original content had a repeating character. | For a workaround, run Remove-Module PSReadLine to unload the PSReadLine module from the current session. This action will not delete or uninstall the module. |
Some keyboard inputs produce strange SAC output (for example, [A, [3~). | VT100 escape sequences aren't supported by the SAC prompt. |
Pasting long strings doesn't work. | The serial console limits the length of strings pasted into the terminal to 2048 characters to prevent overloading the serial port bandwidth. |