@Charles Just to let you and everyone know I fixed the problem. The logger class was trying to open file for writing logs, even when there were no logs, so I added some tests, and now it runs fine. It was my mistake after all..

@Charles No, the application doesn't write anything to the file system. It only reads settings. I implemented a logging mechanism which I used while developing but it is disabled now. I've also tried other Qt application and they run well in read-only mode. I hope I find solution soon. I'll leave a comment here when I do so others know what to do in similar situation. Thanks for great article once again.

Thanks for this. It really gives the stability to micro SD card that I need.

I have one question that may not be really about this topic, but in some way it is. I developed a Qt application which is basically a dummy application. It receives messages and images over UDP sockets, and shows them on the screen. The problem I have is that when I am in read-only mode application just aborts after about half a second or so. When it is run in read-write mode it works great.

After removing chunks of code and testing it in read-only mode I found out that if application don't process received messages, which i really have to since that's the only functionality application has, it doesn't get aborted. I am not that good with Linux to be honest, but what seems logical to me is that when I read that data in application it needs to be stored somewhere, and that somewhere is in read-only part of memory.

Does what I wrote make any sense? If yes which parts of file system need to be mounted as tmpfs to fix it? If not what is actually happening and is it possible to fix it somehow?

By the way I am using Raspbian Jessie Lite if that means something to you.

Thanks in advance