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From: Greg Lehey <grog@lemis.com>
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Subject: Re: Strange df output: what's wrong?
In-Reply-To: <Pine.BSF.3.96.970807010542.7812A-100000@kushnir.kiev.ua> from Vladimir Kushnir at "Aug 7, 97 01:16:33 am"
To: kushn@olinet.isf.kiev.ua (Vladimir Kushnir)
Date: Thu, 7 Aug 1997 10:03:34 +0930 (CST)
Cc: freebsd-questions@FreeBSD.ORG
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Vladimir Kushnir writes:
> Hello all,
>
> I've just noticed that df gives me a strange output for /usr:
>
> Filesystem  1K-blocks     Used    Avail Capacity  Mounted on
> /dev/wd0a       31775    14491    14742    50%    /
> /dev/wd0s2f    826575   657381   103068    86%    /usr
> /dev/wd0s2e     29727     4826    22523    18%    /var
> procfs              4        4        0   100%    /proc
>
> It looks like some 66 Mb just desappeared. I've checked /usr with du and
> it confirms the 657381 Mb space used. This is definitely not swap, and I
> don't see any lost files (or whatever). Nor did I find the possible source
> for this inconsistency in docs. Would please anybody explain what can be
> wrong (if there is something) and how can I fix it?

Well, you don't say exactly what you think the problem is, but I
suspect you mean that the sum of Used and Avail is 66 MB less than the
total.  This isn't just on /usr, by the way.

This is a feature, not a bug.  The last 8% of the file system is
available for use only by root.  100% capacity and the "Avail" column
correspond to the maximum available for allocation by any user.  If
you overfill your file system, you'll see the Capacity field go up to
109%.

See tunefs(8), parameter -m (minfree) for more details.

Greg