I created a 20GB truecrypt container file. I use it to store videos. I store it on an external drive that is always connected to my Win7 daily PC, and only occasionally mount this container file with truecrypt when I need to add new videos to it. I also back up this external drive with another identical external drive.
Recently this 20GB truecrypt container became corrupted, when I mount it I couldn't read all the videos. Out of the 8 videos I had stored in the container, I could only read 2, the rest are all become unreadable. This seems to be a problem with large encrypted file, since one tiny corruption can destroy the entire thing. My backup was corrupted too, since it simply copied the corrupted source file.
I had no problems with smaller truecrypt containers of around 100MB in the past.
So TL;DR: is there a tool or method, that can ensure no corruption will happen to a 20GB encrypted file? (preferably on windows)