[lttng-dev] Error: Unable to list kernel events: Kernel tracer not available

[Kienan Stewart]

Hi François,

On 7/12/24 3:52 PM, François Belias wrote:
> Hi Kienan,
> Yes, `lttng-sessiond` is being run by the root user. I have shared a 
> screenshot of the result when I ran the `lttng-sessiond -vvv` command, 
> but I don't think the kernel modules are loaded.
> thanks
> 
> 

There are two issues in the screenshot you attached:

   1. You are not starting lttng-sessiond as the root user, you are 
running it as the user 'philippe'
   2. The error in the screenshot indicates that there is already 
another lttng-sessiond running.

Could you please stop all of the lttng-sessionds, then run 
`lttng-sessiond -vvv` as the root user?

thanks,
kienan

> Le ven. 12 juill. 2024, à 15 h 24, Kienan Stewart <kstewart at efficios.com 
> <mailto:kstewart at efficios.com>> a écrit :
> 
>     Hi François,
> 
>     On 7/12/24 2:53 PM, François Belias via lttng-dev wrote:
>      > Hello,
>      >
>      > When I run the command `sudo lttng list -k`, I get the following
>     error:
> 
>     To check a few things:
> 
>         * Is lttng-sessiond being run by the root user?
>         * If you run lttng-session with the "-vvv" option, are there
>     messages
>     related to loading the kernel modules?
>         * Once the lttng-sessiond is started, you can check to see if the
>     kernel modules have been loaded by running the following command:
> 
>     ```
>     lsmod | grep lttng
>     ```
> 
>     thanks,
>     kienan
> 
>      >
>      > ```
>      > Error: Unable to list kernel events: Kernel tracer not available.
>      > ```
>      >
>      > I am trying to build LTTng-modules from the source. I followed
>     the steps
>      > from this website: [LTTng
>      >
>     Documentation](https://lttng.org/docs/v2.13/#doc-building-from-source <https://lttng.org/docs/v2.13/#doc-building-from-source>
>      > <https://lttng.org/docs/v2.13/#doc-building-from-source
>     <https://lttng.org/docs/v2.13/#doc-building-from-source>>), but I still
>      > encounter this error. Can someone help me resolve this issue?
>      >
>      > Thanks.
>      >
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