Journald stored in RAM surviving restart

Hello, we are using Colibri VF50 modules successfully with Linux OS. To not wear out flash memory too soon, we have configured journald to be stored only in memory (Storage = volatile). But it will be useful if logged messages retains in log if system restarts (without loosing power).

We successfully applied similar approach with our custom application running on Linux by reducing amount of memory available for Linux OS (by configuration made in U-Boot) - this creates some reserved memory. This reserved memory (with known address) is then used directly by our application to store some data surviving system restart.

My question is - does anybody has an idea, how we could apply the same approach to be used by journald? I was thinking about creating some filesystem over another reserved RAM and then let storing log from journald to this filesystem by using symbolic link. But I’m not sure if tmpfs can be used for this purpose. Very interesting is project pramfs (http://pramfs.sourceforge.net), but unfortunately it’s not maintained and it’s not compatible with latest kernel version.

Thank you in advance for any tips and ideas :slight_smile:

HI @janulo

Could you provide the version of the hardware and software of your module?

We don’t have much experience in doing persistent ram disk but your approach seems to correct. You can also have a look here.

Best regards, Jaski

Hi @jaski.tx , thanks for your reply.

Our module information: Col VF50, V1.2A.
OS: Linux colibri-vf 4.4.73-r2+gc1d5fe2 , custom build.

Regards
Jan

Thanks for this Information.