[SOLVED] Disk usage via df inaccurate - Can't find what is taking up additional space

fincher69 · 10-28-2013, 09:03 PM

Howdy all, I have an ubuntu box and I have a bit of weird behavior concerning disk usage. I have a partition for /home and I have a separate partition mounted to /home/fincher/media-backup. The output of df shows this

Code:

/dev/sda4       1.8T  1.4T  353G  80% /home
/dev/sdb1       1.8T  728G 1014G  42% /home/fincher/media_backup

Yet the output of du for /home shows this.

Code:

16K	./lost+found
716G	./fincher
716G	.

If I run du without the -x option (which makes it exclude ~/media-backup I get this

Code:

16K	./lost+found
1.5T	./fincher
1.5T	.

This makes sense because a bulk of what I have in my home folder is media that is backed up on the other partition.

My question is whether I might be seeing faulty output from df. If not, then I would appreciate any help in figuring out why df seems to think I am taking up almost double the space that I should be. Any insights would be greatly appreciated.

fincher69 · 10-29-2013, 10:03 AM

I figured it out. Turns out I had set up a cronjob to backup my media and, at some point, the partition to which it backs up hadn't gotten mounted. So it backed up everything to that folder on the /home partition. Since then, the partition had been mounted on that folder so I couldn't see that there were backups there. Doh!

Habitual · 10-29-2013, 11:36 AM

Code:

if mountpoint -q /media/backup1
then
do work
else
mount the drive
fi

should help your script out.