Problem understanding df (diskfree) output for ext2fs

wirawan0 · 10-15-2003, 07:59 PM

Hi,

I have a question on `df' output for ext2 filesystem. See the following example:

Code:

Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/hda7              6846744   5557528    941412  86% /
/dev/hda6              8161222   5081082   3080140  63% /d

The / filesystem (ext2fs) is said to have only 941412 blocks free, while if we compute "avail - used", it gives 1289216 blocks. Now, the /d is an FAT32 filesystem, it gives the consistent answer: 8161222 - 5081082 = 3080140. Why is this? Can somebody explain? I don't understand ext2fs that much.

Wirawan

michaelk · 10-15-2003, 08:32 PM

By default when you format a ext2 partition it reserves 5% for roots use only and not accounted for as avilable space. Its supposed to keep fragmentation down as well as allow root to log in in case the partition fills up.

so:
total= used + available + 5%total