[CentOS] How do I check the real size of a filesystem?

[William L. Maltby]

On Fri, 2008-07-04 at 14:09 +0100, Kevin Thorpe wrote:
> > Kevin Thorpe wrote:
> > > I'm having a spot of bother with a large (900GB) partition.
> > > fdisk claims it's 900GB. I made an ext3 fs on it and df says it's 
> only
> > > 94GB. Which is correct? Or did I do something wrong?
> > 
> > If this partition is on a LARGER drive, you may need to use 
> > parted and 
> > not fdisk to create your partitions.  Large drives need gpt 
> > labels and 
> > are not able to be partitioned with fdisk.
> > 
> > However, that is not usually a problem with 900GB drive.
> 
> parted claims it's 879GB so the partition appears to be ok. Have I
> managed to format a small filesystem on a large partition?

I suggest running e2fsck -n. See the man page. Then, think of the -m
parameter. The default, IIRC, is 5%. On small drives of the past this
was appropriate. Now, I make most of mine with 1%.

900GB * .05 = appx. 45GB. There's your loss.

> <snip>

HTH
-- 
Bill