On Tue, Mar 24, 2009 at 02:34:09PM +0100, Jerome Warnier <jwarn...@beeznest.net> wrote: > Giacomo A. Catenazzi wrote: > > Jerome Warnier wrote: > >> Raphael Hertzog wrote: > >>> On Tue, 24 Mar 2009, Jerome Warnier wrote: > >>> > >>>> For files from packages, though, deduplication might be a good > >>>> idea, as > >>>> dpkg is supposedly the only one to ever modify the files (under > >>>> /usr for > >>>> example). > >>>> I don't know however how dpkg treats hardlinks. Does it "break" the > >>>> hardlink before replacing a file or does it replace the file whatever > >>>> its real nature is? > >>>> > >>> IIRC dpkg preserves hardlinks inside a binary package but I don't > >>> see how > >>> it could do the same across multiple binary packages. > >>> > >> Oh, I didn't expect it to. I just wanted to know its behaviour when it > >> upgrades a package. > >> Before the upgrade, the file is a hardlink (because I hardlinked it > >> manually), then it tries to upgrade the file/hardlink. Does it "break" > >> the hardlink* before upgrading the file or does it overwrite the > >> file/hardlink and all of its "siblings"? > > > > Do you really care? (not theoretically, but in normal use). > > I would expect that same content will be delivered: > > - by "brother" packages (same source), thus usually updated > > at the same time. > > - in documentation (so maybe not so important for your use). > > > > I think the most problem are in files outside "dpkg" control, > > i.e. /var and /etc. > > > > I'm just curious: do you have a list of "same" content files? > > maybe I'm completely wrong. > Here you are, for /usr on a typical Lenny AMD64 server (generated with > "finddup -n" from package perforate): > http://glouglou.beeznest.org/~jwarnier/usr-duplicates.list.gz
$ zcat usr-duplicates.list.gz | awk '{t+=$1*(NF-2)}END{print t}' 33142129 You would free 33MB. How big is your disk ? Is it worth bothering ? You can get much more free space than that by reducing the number of inodes supported by your filesystem: For instance, on my / fs, that contains /usr, and is only 3GB: Inode count: 384000 Free inodes: 314133 I will obviously never use that many inodes... Now, consider an inode is 128 bytes (or even 256 in some cases), and do some maths... Mike -- To UNSUBSCRIBE, email to debian-devel-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org