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I am running centos 5. So far, it gives no problem but just yesterday, when it reported "no free space" for file writing, I try to remove some file as usual. Unfortunately this time no matter how much files I had deleted, it just keep showing no available space for doing so.

Result from df:

[root@LSMSVR ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
                      1.2G  269M  879M  24% /
/dev/hda6             4.8G  138M  4.4G   4% /tmp
/dev/hda5              19G  2.4G   16G  14% /usr
/dev/hda3              48G   12G   34G  25% /var
/dev/hda2             379G  365G     0 100% /home
/dev/hda1              99M   15M   80M  16% /boot
tmpfs                 180M     0  180M   0% /dev/shm

Any idea how to recover the lost space in /home? Thank you.

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up vote 4 down vote accepted

Default for linux file-systems is that 5% is reserved for root access only - that's why you don't see it. You can see this number when comparing "size" and "used"

You can change this to 1% by going sudo tune2fs -m 1 /dev/hda2 Obviously you can change the -m parameter to any number of percent.

Note! It may seem like a good idea to set this parameter to 0 for all drives, but your system may lock you out altogether if the hard-drive fills up. (not an issue on non-root disks)

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There is no "lost space". By default 5% of the space on a filesystem is reserved for root, so that users don't fill it up completely and kill the system. Keep removing files until there is more than 5% free space left in the filesystem. You have at least another 5GB or so to go.

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Is default of 5% specific to the filesystem? – bbaja42 Jun 16 '11 at 6:25
It's specific to the program used to create the filesystem. Of course, some filesystems don't support it at all. – Ignacio Vazquez-Abrams Jun 16 '11 at 6:28
How did you detect in the question which filesystem is used in this case? – bbaja42 Jun 16 '11 at 6:30
CentOS 5 means ext3. But ext2/3/4 all support it. – Ignacio Vazquez-Abrams Jun 16 '11 at 6:32
tune2fs can be used to modify the parameters of a ext2/3/4 filesystem, but I recommend that you don't set the reserved percentage all the way down to 0. – Ignacio Vazquez-Abrams Jun 16 '11 at 6:57

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