# DDB over IPMI-sol



## da1 (Aug 19, 2011)

Hi guys,

We have a 8-STABLE machine and while talking about it yesterday at work, the subject of DDB via IPMI-SOL came up. I did a quick search and came across 10.4 On-Line Kernel Debugging Using DDB handbook section. After reading it a couple of times, I realized that the first option ( the "-d" boot flag) doesn't apply to our needs (as the server is in the DC and we would need to go there) and the second option (to drop to DDB via 
	
	



```
sysctl debug.kdb.enter=1
```
 doesn't work over a SOL session. However, I saw this:


> There is an option available for serial consoles that allows the use of a serial line BREAK on the console line to enter DDB (options BREAK_TO_DEBUGGER in the kernel config file). It is not the default since there are a lot of serial adapters around that gratuitously generate a BREAK condition, for example when pulling the cable.


This might be something we could use but I have a hard time understanding the BREAK concept and I'm not really sure that this will provide the functionality we require.

The idea is to have DDB access via IPMI-sol (if possible).

Any thoughts ?


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