From mboxrd@z Thu Jan 1 00:00:00 1970 From: Valerie Aurora Subject: Re: [PATCH 0/5] hybrid union filesystem prototype Date: Tue, 31 Aug 2010 15:29:19 -0400 Message-ID: <20100831192919.GB5759@shell> References: <20100826183340.027591901@szeredi.hu> <20100827170551.19616048@notabene> <20100827213502.31af4a4c@notabene> <20100829144207.4fbf2713@notabene> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Neil Brown , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk, jblunck@suse.de, hch@infradead.org To: Miklos Szeredi Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Mon, Aug 30, 2010 at 12:18:11PM +0200, Miklos Szeredi wrote: > On Sun, 29 Aug 2010, Neil Brown wrote: > > > My comment about set-theory unions being commutative set me thinking. I > > really don't think "union" is the right name for this thing. There is > > nothing about it which really fits that proper definition of a union. > > whiteouts mean that even the list of names in a directory is not the union of > > the lists of names in the upper and lower directories. > > "overlay" is a much more accurate name. But union seems to be the name > > that is most used. I wonder if it is too late to change that. > > We could call it overlayfs. People learn new names quickly :) Union mounts was named "writable overlays" for one release in an attempt to get away from the "arbitrary union of file systems" idea. I think it helped, but went back to union mounts since it was more familiar and made prettier function names. The config option for union mounts says: Union mounts allow you to mount a transparent writable layer over a read-only file system, for example, an ext3 partition on a hard drive over a CD-ROM root file system image. -VAL