[OT] Hardlinks and directories

[Patrick O'Callaghan]

On Fri, 2010-02-12 at 15:40 -0800, Suvayu Ali wrote:
> On Friday 12 February 2010 09:19 AM, Mikkel wrote:
> > On 02/12/2010 09:29 AM, Bruno Wolff III wrote:
> >>
> >> lsof would allow you to find the processes that have the files open. And then
> >> you could kill those processes to release the space. It looks like you should
> >> be able to get size infomation of these files from lsof as well. So one
> >> could script looking for processes that have large files open.
> >
> > You might want to try using the +L1 and the -s options. It will
> > display the sizes of unlinked (deleted) files.
> >
> > lsof +L1 -s
> 
> I am not entirely clear about this part, how does one end up with an 
> un-named open file. To simulate the situation I tried to open a text 
> file with an editor and then removed it with rm. But it doesn't show up 
> in `lsof +L1' as I was expecting it to. Am I understanding this the 
> wrong way?

Editors can do funny things with backup files in the interests of
preserving your work. An easier test would be:

cat > foo &
rm foo
lsof +L1 -s

When I do this the "cat" process shows up (and foo is marked as
deleted). You can then reconnect to "cat" (using fg) and write stuff
into the "non-existent" file.

poc