[Techtalk] Different usage betweed df and du

[Sue Stones]

Mary wrote:

>This is actually rather useful. It allows you to do really quite
>fundamental things like upgrading libc, which practically everything
>uses, *without rebooting*. 
>  
>
That is very cool in my opinion.

> 2. in your situation, it can mean that deleting something doesn't free
>    up disk space, because a long running process still has the deleted
>    version open. This is Conor's theory. It's quite easily testable if
>    you reboot: rebooting will force all processes to stop. If you
>    reboot and df and du still disagree, Conor's theory has been
>    falsified :)
>
Well after deleting a few things and saving what I was working on, 
rebooting was the first thing that I did.  Before posting here, it made 
no difference to the numbers reported by du or df.  So it doesn't seem 
like that is the problem.

The "self tests" on the disc finished too, and its still reporting no 
errors. At least that suggests that the disc is not going to fail in the 
middle of my current (uni) project (due next week).

Is there anything else that could be taking up space but not visible to 
the filesystem?

sue