Mysterious drive capacity numbers....?

[Loïc Grenié]

2010/12/14 Karl Auer <kauer at biplane.com.au>:
> Hi all.
>
> I have a conundrum.
>
> here are lines from "mount" and "df -k" showing a connected USB hard
> disk:
>
> /dev/sdb1 on /media/nc1 type ext3 (rw,nosuid,nodev,uhelper=hal)
>
> Filesystem           1K-blocks      Used Available Use% Mounted on
> /dev/sdb1            961432072  57820632 854773440   7% /media/nc1
>
> Note that the amount used is given as 57,820,632K - about 57GB.
>
> But 961 - 854 = 107. Where did the extra 50GB go?

    That's 5% reserved "for root". Any non-root user can put data on the
  drive as long as used space is less than 912594072k. As soon as used
  space goes above 912594072k, only root can write (up to 961432072k).

        Hope this helps,

          Loïc