Using Mincom with a SmartServer IoT to fix other SmartServer IoTs (KB1437)

This article describes how to use minicom with a SmartServer IoT (sometimes called a host SmartServer) to access another SmartServer's console port.  A host SmartServer is used to stop a problem SmartServer from constantly rebooting or stop the problem SmartServer in its U-boot prompt. 


Some SmartServer IoTs may get into a mode where it is constantly rebooting. This may occur after a re-image, glpo update or due to corruption.   To fix the SmartServer you will want to stop the SmartServer from rebooting and stay in the U-boot prompt and then issue the required commands to fix the SmartServer.


You can only stop the boot process temporarily, eventually the SmartServer will continue the boot process if you are not entering commands. So some instructions specify you copy all the commands in one copy and do one paste to the problem SmartServer console.


The SmartServer doesn't include minicom so you will need to install it before you can use the host SmartServer to fix problem SmartServers.  Once you setup minicom on one SmartServer that SmartServer can be used to fix any problem SmartServer.

Since stopping the boot process is only temporary, it is best to read these instructions and have any commands that need to issue handy otherwise the SmartServer may re-start the boot process before you can issue the commands.


Using a host SmartServer IoT:

1. Use SSH or console from your PC to a Host SmartServer.

   - For putty users only: putty doesn't report its screen size correctly (which affects minicom) so once you access the problem SmartServer you may see lines overwrite each other

        - Right-click on the Putty terminal and select "Change Settings" and select Window.

        - Change the Columns and rows size, and click apply. 

            -  For example set columns to 255 and Rows to 24 works.

            -  Other values will also work  but you may see some more line overwritten.

2. Plug console cable between the host SmartServer and the problem SmartServer

   - Plug the larger USB A side into one of the 4 Host SmartServer USB ports.

   - Plug the smaller USB cable into the problem SmartServer console port.

3. Host SmartServer: Install minicom

sudo apt update
sudo apt install minicom

4. Host SmartServer: Configure Minicom

sudo minicom -s

4.a Host SmartServer: cursor down to "Serial port Setup" and click the enter key


4.b Host SmartServer: Click "F" character to disable flow control (set to no) when done press the enter key to save 

BPS 115200 8N1, no flow control


BPS 115200 8N1, no flow control

4.c Host SmartServer: Cursor down to save setting in the dfl file and press the enter key


4.d Host SmartServer: Cursor down to Exit from Minicom and press the enter key.



5. Host SmartServer: Determine which USB port (0-3) is used on the host SmartServer

ls /dev/ttyUSB*


6. Host SmartServer: Start Minicom using ttyUSBX where X is the port 0-3.

sudo minicom -D /dev/ttyUSB0

7. Problem SmartServer: Communicate to the problem SmartServer: Abort boot process by pressing any key or log into Problem SmartServer.

Stopping the boot process in the U-boot is temporary. So when sending commands you may need to copy and paste all the commands as a single paste. 

If see lines in Putty are getting overwritten in minicom, please see step 1 on how to change Putty column and row settings.

For example, 

To see environmental settings.


re-save the SmartServer environmental variables, which can fix some constant reboot issues.

env default -a

To re-image the SmartServer from the U-boot prompt see KB1438.

The Smartserver will automatically boot up after a short period of time.

8. Host SmartServer: Exit Minicom, use capital "X".





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