Most troubleshooting requires access to a console and a login prompt. There are three primary methods to connect to your device for troubleshooting. All three methods will lead to a text login with the username of "root" and no password. Obviously these images should not be used for production devices.
The simplest method to connect to your device is with an HDMI display and a USB keyboard. The Beaglebone requires a micro-HDMI to HDMI cable or adapter. The Raspberry Pi uses a standard HDMI to HDMI cable.
An alternative to HDMI and keyboard is to use a serial adapter; this can provide more effective troubleshooting since it allows for easy copy/paste/search of the console output. This does require additional hardware.
For the Beaglebone, use this link as a reference.
On Windows, the following applications can be used to access the serial console:
On Linux, you can use picocom, screen or minicom. These are all available in the Ubuntu package repository. For other distributions, the standard package install mechanism likely will have these as well. Note that these are all console apps and may also work on MacOS or Windows.
The Yocto builds will have OpenSSH installed and configured by default.
This generally means that the Beaglebone was booted from the on-board eMMC rather than the SD-Card. To fix this, please power off the system and make sure to depress switch S2 while powering back on (keep the button pressed for 5 seconds while the device starts up).
This generally means there is an issue with your SD Card. Please try another SD Card. Also, please make sure after creating the SD Card it is automatically mounted when inserted in your desktop system. Note: if you are on Windows, you may not see multiple partitions as they are not Windows compatible.
This likely means there was a kernel crash or some other issue with the system startup code. Please capture the output that is available and contact Mender support for more guidance.
This likely means that your image is incorrect. Please retry your SD Card provisioning.
The primary cause of issues using Mender relate to networking. Use the following command to determine if your network is connected properly:
# ping 188.8.131.52
If you are unable to ping the above server (it is one of the Google DNS servers and should be online) your basic network connectivity is non-functional. Please check your cabling. Type:
# ip addr
To see what, if any, IP address was assigned to your device.
If these steps fail, consult your local network administrator to understand why you are not getting internet connectivity. Many lab environments are locked down and may require special site procedures to allow the devices to connect.
Run the following to attempt to contact the Mender server:
# echo string | nc hosted.mender.io 443
Note, replace hosted.mender.io with the URL of your server if you are using an on-premise installation
The result should be a message containing "400 Bad Request". If the command hangs or produces any other error message, then the connection to the Mender server has failed. Please consult your local network administrator for further troubleshooting.
Proper certificate processing requires an accurate system time. See Mender Client troubleshooting for more details.
If the above tests all pass, then please review Mender Client troubleshooting to help determine next steps.