Explaination needed for strange `df` and `du` results

Can someone help me to understand the following output:

# df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/xvda1      8.0G  7.5G  167M  98% /
udev            7.4G  8.0K  7.4G   1% /dev
tmpfs           3.0G  200K  3.0G   1% /run
none            5.0M     0  5.0M   0% /run/lock
none            7.4G     0  7.4G   0% /run/shm

I don't find any folder taking that much space in /. I assume it is being taken by temp processes but not too sure.

I am not sure why do we have the udev (7.4G) and none (7.4G)?

# df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            7.4G  8.0K  7.4G   1% /dev
tmpfs           3.0G  200K  3.0G   1% /run
none            7.4G     0  7.4G   0% /run/shm

I have checked manually du -sh /*. Should I assume the disk is being taken by temporary filesystem? See the following output:

  # du -sh /*
  8.7M    /bin
  19M     /boot
  4.0K    /data2
  8.0K    /dev
  5.9M    /etc
  196M    /home
  0       /initrd.img
  80M     /lib
  4.0K    /lib64
  16K     /lost+found
  4.0K    /media
  20K     /mnt
  4.0K    /opt
  du: cannot access `/proc/21550/task/21550/fd/4': No such file or directory
  du: cannot access `/proc/21550/task/21550/fdinfo/4': No such file or directory
  du: cannot access `/proc/21550/fd/4': No such file or directory
  du: cannot access `/proc/21550/fdinfo/4': No such file or directory
  0       /proc
  4.6M    /root
  200K    /run
  9.4M    /sbin
  4.0K    /selinux
  4.0K    /srv
  0       /sys
  4.0K    /tmp
  757M    /usr
  343M    /var
  0       /vmlinuz

smkengr

Posted 2013-05-28T10:39:14.300

Reputation: 31

I can not reboot the machine. – smkengr – 2013-05-28T11:00:07.030

7.5G are not unusual for your root filesystem with packages installed. You could try removing and cleaning old packages with sudo apt-get autoremove and sudo apt-get autoclean. – André Stannek – 2013-05-28T11:25:58.340

1but I think installed packages should show the disk consumption in /usr /var /opt or anywhere in the system. isn't it? sudo apt-get autoremove and sudo apt-get autoclean ... didn't help – smkengr – 2013-05-28T12:42:58.147

1Maybe some big files are still held hostage by running processes though they are technically deleted? try sudo lsof | grep DEL and restart the relevant processes in the left column. – Patrice Levesque – 2013-05-28T14:11:05.943

Explaination needed for strange `df` and `du` results

No answers