Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have an Ubuntu 11.04 64 bit development image running on VirtualBox. I have been doing some house keeping on the disk space because it was getting low. The drive is a 26GB drive. I have about 4.7 GB going to swap. That leaves about 21 GB of total space. I ran the Disk Utilization software and discovered some of the folders that were taking up too much space and deleted them. I also ran aptitude cleanup commands which freed about another 1 GB of space. Now I am sitting on 10.5 GB of used space. (Displayed in the Disk Usage Analyzer) Nautilus is only displaying about 7.5GB free space on the drive. That doesn't make sense in my mind. 21 minus 10.5 is not 7.5.

I wanted to make sure that those tools were not showing incorrect information so I ran a df -h. That displays 11G used and the size of the drive 20G. 7.5 Available. That still leaves a discrepancy of 1.5 GB.

I know you can't get exact but that discrepancy is huge. Is there anything that I could be missing?

share|improve this question
Did you have a look in 'Disk Utility'? It shows the hard drives with the partitions on them, you could check to see how much each partition is taking and where the extra space went. – Mendhak Jan 25 '12 at 20:31
up vote 1 down vote accepted

Depending on the filesystem, 5% of the space on your disc are reserved for the superuser and not shown by df.

You can increase/decrease this with tools like e2fstune (if your filesytem is something like ext2/3/4).

share|improve this answer
You are absolutely correct. Uggghhh. I can't believe I forgot that the space was allocated to the superuser. That is what I get for using multiple operating systems. I completely forgot about that. I did the math and it came up to the correct missing space. Thank You. – Jim Jan 25 '12 at 21:17

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.