Disk usage oddity

[Phil Stovell]

I'm running Ubuntu Breezy on a Dell Dimension 8100. I have a 60GB (hda),
with Windows ME installed and a 160GB (hdb) with Ubuntu.

If I type "df -h" it tells me Size=147G, Used=105G, Avail=34G for
/dev/hdb1. 105G + 34G != 147GB. The Windows partition is not mounted.

However, if I select all directories in / using root Nautilus and do
properties, it tells me I've used 46.3GB.

How can I find where the missing 58.7GB is?

Thanks.

--
Phil Stovell, South Hampshire, UK

Save Gales Brewery
[url]http://www.savegales.org.uk/[/url]

[Jim Howes]

Phil Stovell wrote:

> I'm running Ubuntu Breezy on a Dell Dimension 8100. I have a 60GB (hda),
> with Windows ME installed and a 160GB (hdb) with Ubuntu.
>
> If I type "df -h" it tells me Size=147G, Used=105G, Avail=34G for
> /dev/hdb1. 105G + 34G != 147GB. The Windows partition is not mounted.

ext2 and ext3 filesystems, in common with a number of other unix filesystems
reserve a certain percentage of data blocks for root's use, so users cannot
bring the system to a complete standstill by filling the disk. This is
typically 5%. It can be changed using the tune2fs -r option, although
eliminating it altogether for anything but removable storage media is a bad idea
because the volume will probably become horribly fragmented over time. (Linux
does not, on the whole, require any sort of 'defragmenter' program because the
disks do not get fragged in the first place, because the block allocation code
is somewhat more clued than the windows FAT32 equivalent, but it's algorythm
depends on there always being a certain amount of free space available)

> However, if I select all directories in / using root Nautilus and do
> properties, it tells me I've used 46.3GB.

It is probably following hard or soft links, or decending into other filesystems
(/proc is a good one; there are some large 'files' in /proc, which are not
files, nor are they on your disc).
Hard links can be used to make the same file appear under more than one name.
(The OS knows files on a disk by inode number, directories link names to inodes;
having two directory entries which point at the same inode means that the same
file is known by multiple names)
Unrestricted use of hard links is a bad idea because it causes no end of confusion.
Soft links are simply pointers to other files, and the system follows these
automatically, so a file can then appear to be in two(or more) places at the
same time. Software that transparrently follows soft links by default is
probably broken (although this depends on context).

> How can I find where the missing 58.7GB is?

It probably isn't missing.

[Henning Præstegaard]

Phil Stovell wrote:

> I'm running Ubuntu Breezy on a Dell Dimension 8100. I have a 60GB
> (hda), with Windows ME installed and a 160GB (hdb) with Ubuntu.
>
> If I type "df -h" it tells me Size=147G, Used=105G, Avail=34G for
> /dev/hdb1. 105G + 34G != 147GB. The Windows partition is not mounted.
>
> However, if I select all directories in / using root Nautilus and do
> properties, it tells me I've used 46.3GB.
>
> How can I find where the missing 58.7GB is?
>

Its because your harddrive is in decimal and linux and windows is in binary.
[url]http://www.qindex.info/Q_drctry/miscellaneous_tips/Binary_Multiples.asp[/url]
[url]http://physics.nist.gov/cuu/Units/binary.html[/url]

160GB/1GiBi=149


Henning

[Robert Billing]

Among the wreckage we found a fragment on which Phil Stovell had
scratched:

> How can I find where the missing 58.7GB is?

du -x -h --max-depth=1 /

[Phil Stovell]

On Tue, 21 Feb 2006 09:04:45 +0000, Robert Billing wrote:

> Among the wreckage we found a fragment on which Phil Stovell had
> scratched:
>

>> How can I find where the missing 58.7GB is?

>
> du -x -h --max-depth=1 /

Thanks for that! It looks like Nautilus was ignoring a couple of hidden
directories containing digital photos.

Thanks to everybody for their assistance.

--
Phil Stovell, South Hampshire, UK

Save Gales Brewery
[url]http://www.savegales.org.uk/[/url]