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Date: Mon, 10 Nov 2008 17:10:03 +0100
From: Jille Timmermans <jille@quis.cx>
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Cc: FreeBSD Stable <freebsd-stable@freebsd.org>
Subject: Re: du and df don't agree
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Probably some file descriptor to an unlinked file is still open.
The space on disk will be freed when the last descriptor is closed.
and because there is no file linked to the data, du can't see it.

(iirc MySQL does this in some situaties when using temp-tables or 
rebuilding tables)

-- Jille

Stephen Clark wrote:
> Why would du show 630k used by /tmp while df show 161M used
> by /tmp?
>
>
> # du -sh /tmp
> 630K    /tmp
> # df -h
> Filesystem     Size    Used   Avail Capacity  Mounted on
> /dev/ad0s1a     94M     41M     45M    47%    /
> devfs          1.0K    1.0K      0B   100%    /dev
> /dev/ad0s1e    193M    161M     17M    91%    /tmp
> ... remaining fs info removed
>
> # uname -a
> FreeBSD 6.1-STABLE FreeBSD 6.1-STABLE
>
> I have run fstat /tmp and can't find any files that are using
> the space that df is claiming as being used.
>