[H-GEN] MySQL filling up /

[Greg Black]

On 2004-01-06, Michael Anthon wrote:

> The real thing I can't understand is how mysql was able to use up 4G of
> space on the disk without me being able to find out where it was doing
> it (and yes, tmpdir was set to /tmp and I know how to show hidden files)
> 
> Can anyone shed some light on this for me?

The standard answer is that some program opens a file (often for
temporary purposes) and then immediately unlinks it while
keeping the file open.  This causes the file to be invisible to
du and ls; but, since it takes space, the reduction in free
space is apparent to df.

The useful consequence is that the file will disappear when the
process exits without any further effort.  The problem is that
this makes some problems hard to resolve.

I have no idea whether mysql does this, but it's the first place
to look.

This is why I make /tmp a (big) separate partition.

Cheers, Greg