I am looking for a way to visualize writes to a big file (2GB) in real-time. The writing process isn't just appending data to the end of the file. Instead, it acts like a container or like a block device. So data is written anywhere within the file.
Is there a tool that shows me which parts of the file are changing? It does not need to be precise - in fact - I just need to know wheter it's at the beginning, in the middle or end of the file. Best would be a tool that works on the CLI.
I was unable to find such a tool, but maybe someone here can help.