From owner-freebsd-questions  Thu Nov 18  8:51: 7 1999
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From: Richard Tobin <richard@cogsci.ed.ac.uk>
Subject: Re: "whiteouts" in rm manpage
To: Dann Lunsford <dann@greycat.com>, questions@FreeBSD.ORG
In-Reply-To: Dann Lunsford's message of Thu, 18 Nov 1999 06:20:46 -0800
Organization: just say no
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> WHITEOUTS???  What is this?

IIRC, whiteouts are (would be?) used for the union filesystem (similar
to Sun's "translucent" filesystem).  The union filesystem allows one
filesystem to be mounted "over" another, where you see files in both
filesystems with those in the "upper" filesystem overriding those in
the (typically read-only) "lower".  A whiteout in the upper filesystem
hides one in the lower, allowing you to delete files from the union.
Undeleting such a whited-out file would just be a question of removing
the whiteout to expose the original again.

-- Richard


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