0
# df -h
Filesystem                    Size  Used Avail Use% Mounted on
/dev/mapper/vg_bgsvn-lv_root   28G   26G  416M  99% /
tmpfs                         495M     0  495M   0% /dev/shm
/dev/sda1                     485M   54M  407M  12% /boot
/dev/sdb1                     126G  3.3G  116G   3% /r1_72k_data2
\\xx2\repositories            106G  8.4G   97G   8% /mnt/repositories


# du -h --max-depth=1 /
16K     /lost+found
3.1G    /r1_72k_data2  <---Mounted Directory/Drive in there
0       /proc
0       /sys
43M     /boot
4.0K    /srv
26M     /etc
14M     /sbin
25M     /lib64
4.0K    /media
172K    /dev
239M    /lib
41M     /var
346M    /mnt
4.0K    /selinux
806M    /usr
3.3G    /opt    <----Mounted directory/drive in there
33M     /tmp
6.0M    /bin
76K     /home
64K     /root
7.9G    /

There should be over 20GB of file space left! It seems I am missing something big but don't know what. Could swap be taking this?

HBruijn
  • 72,524
  • 21
  • 127
  • 192
cshenderson
  • 11
  • 3

1 Answers1

1

First, some space is reserved for rootuser. You can check how much space is reserved for root,with: 

tune2fs -l /dev/mapper/vg_bgsvn-lv_root

This will give you the block count reserved for root user, multiply it by the block size and you will get the size of reserved space (in bytes).

Second, most probably some file descriptors are still in use. That means that a file seems to be deleted but still it is in use and process writes to it. Although you don't see the file anymore on FS a process still is using the file. If you stop/kill the process or reboot the system, the used space will be released. You can look for deleted files with: 

lsof | grep deleted

This is a story old as Unix and Linux systems, if you search on stackexchange for "du and df" you will find a lot of answers.

b13n1u
  • 980
  • 9
  • 14