That fstab looked pretty normal, I think the next bit you pasted is more 
relevant...

On 09/09/2012 08:00 AM, Dirk Brandherm wrote:
> Filesystem	1k-blocks	Used		Available	Use%
> 		51606140	51604044		0	100%

Wow! That's pretty full and looks like your problem has been found.

The disk free (df) command told you that, and the disk used (du) command 
can tell you where all that space is being used. An easy way to get a 
full summary is:

du -shx /*

This may take some time to complete execution since it needs to run 
through the whole device. My guess is that your recent software 
installation was a lot larger than you expected and /usr or /var is 
probably huge now.

/var could be huge because of other software as well, though, since 
variable state data is saved there -- things like database storage 
files, logs and the like that tend to grow with time.

Since you are using a logical volume you can add another physical drive 
and extend the volume to include [part of] it. Or even better, you can 
move /var to its own partition if its the culprit (my usual approach).