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.
Seekwatcher uses
blktrace
underneath and can provide you all kinds of information about disk activity. It can analyze existing blktrace dump files or start blktrace for you. Seekwatcher is probably not exactly what you are looking for, but maybe it can serve as a starting point.Also look for blktrace analyzers, perhaps there are others lurking somewhere out there. +1 for interesting question, anyway!