can't get df to work

plebetan · 01-16-2009, 02:09 AM

hi. i'm trying to find out my disk usage for my root drive, which is /dev/hda6. when i run

Code:

df -h /dev/hda6

i get:

Code:

Filesystem            Size  Used Avail Use% Mounted on
-                     245M   44K  245M   1% /dev

which seems to be bad output.

chakka.lokesh · 01-16-2009, 02:20 AM

why it seems to be bad output?

Didier Spaier · 01-16-2009, 03:19 AM

/dev/hda6 is *not* your root file system. It is your swap partition, this why it shows a hyphen under "Filesystem" and "/dev" under "Mounted on".

You can check that looking at /etc/fstab.

So type "df -h" instead.

nflenz · 01-16-2009, 08:31 AM

Code:

$ df -h | grep '/$'

plebetan · 01-16-2009, 04:14 PM

here is my fstab:

Code:

/dev/hda5        swap             swap        defaults         0   0
/dev/hda6        /                ext3        defaults         1   1
/dev/hda1        /mnt/windows     ntfs-3g     umask=077        1   0
#/dev/cdrom      /mnt/cdrom       auto        noauto,owner,ro  0   0
/dev/fd0         /mnt/floppy      auto        noauto,owner     0   0
devpts           /dev/pts         devpts      gid=5,mode=620   0   0
proc             /proc            proc        defaults         0   0
tmpfs            /dev/shm         tmpfs       defaults         0   0

doing "df -h" shows a root partition mounted as /dev/root. it seems that there is a symlink(/dev/root) out in /dev that points to hda6.

i still don't see why "df /dev/hda6" isn't working.

Didier Spaier · 01-16-2009, 04:55 PM

Would you mind posting whole "df -h" output ?

plebetan · 01-16-2009, 10:13 PM

Code:

Filesystem            Size  Used Avail Use% Mounted on
/dev/root              17G  3.5G   13G  22% /
/dev/hda1              38G  6.0G   32G  17% /mnt/windows
tmpfs                 245M     0  245M   0% /dev/shm

Didier Spaier · 01-17-2009, 03:52 AM

This is what I have:

Code:

bash-3.1$ cat /etc/fstab
/dev/hda3        swap             swap        defaults         0   0
/dev/hda1        /                reiserfs    defaults         1   1
/dev/hda2        /home            reiserfs    defaults         1   2
#/dev/hda4        /12.1            reiserfs    defaults         1   2
#/dev/cdrom      /mnt/cdrom       auto        noauto,owner,ro  0   0
/dev/fd0         /mnt/floppy      auto        noauto,owner     0   0
devpts           /dev/pts         devpts      gid=5,mode=620   0   0
proc             /proc            proc        defaults         0   0
tmpfs            /dev/shm         tmpfs       defaults         0   0
bash-3.1$ df -h
Sys. de fich.         Tail. Occ. Disp. %Occ. Monté sur
/dev/hda1              16G  5,1G   11G  33% /
/dev/hda2              49G   31G   19G  63% /home
tmpfs                 506M     0  506M   0% /dev/shm
/dev/hda4             8,3G  5,6G  2,8G  67% /12.1
bash-3.1$ ls -l /dev/root 
lrwxrwxrwx 1 root root 4 2009-01-17 10:56 /dev/root -> hda1
bash-3.1$

So I don't really see where your problem come from. May be you could tell us what is your distribution and version and how /dev is populated (do you use udev) ?

Anyway if /dev/root points to hda6 you know you have 33G available on it

plebetan · 01-17-2009, 05:54 PM

i'm using slackware, and /dev/root does point to /dev/hda6. i just think its weird that i can only get my disk usage info by doing "df /dev/root", when i want to call it /dev/hda6. i think the problem is that it's mounted as /dev/root, so df must look at whats mounted and not understand that /dev/root and /dev/hda6 are the same thing.

servat78 · 01-18-2009, 06:39 PM

If you want to find out the disk usage for your root drive, why not using
$ df -h /

Your root device is located on /dev/hda6, but even so it is mounted as /
I really see no point of running df with some device, as it can deal only with mounted devices and even that only via the mountpoints.

/dev/root is special case on a UNIX system and obviously related to the root mountpoint, and certainly not meant to used by df.

Debian