OK, so another results, I used different data, because the apt cache is moving target and I not do backup of the last data...
0) 129 files: 268 706 070B - 100% 1) xz for control.tar.xz and data.tar.xz, all *.gz inside debs ungziped: 186 814 608B - 69.5% 2) 7z-gzip for control.tar.gz, xz for data.tar.xz, all *.gz inside debs ungziped: 186 822 308B - 69.5% 3) 7z-gzip for control.tar.gz, xz for data.tar.xz, all *.gz inside debs recompressed to xz: 187 681 956B - 69.8% 4) like 1) + PNG optimization (advdef, optipng, pngcrush, pngopt): 186 750 504B - 69.5% Decompression of all gzip files inside the deb will save 0.3%. Recompression of control.tar to xz gives little smaller size overall (some files bigger some smaller). PNG optimization gives also little smaller size. Note that I am not dpkg developer either zlib developer, I am only user. TonyMi > ------------ Původní zpráva ------------ > Od: Christian Leber <[email protected]> > Předmět: Re: Experiment with using 7z for gzip compression of packages > Datum: 17.4.2011 23:14:57 > ---------------------------------------- > On Sun, Apr 17, 2011 at 10:05:53PM +0200, [email protected] wrote: > > Hello Tonda > > > 0) 1132 packages (I used my apt cache): 1 076 539kB - > > 100% > > 1) recompress the control.tar.gz and data.tar.gz: 1 038 391kB - 96.5% > > 2) + recompress all *.gz files inside the data.tar.gz: 1 022 712kB - > > 95.0% > > 3) like 1) but with xz: 752 202kB - > > 69.9% > > 4) like 2) but with xz: 727 946kB - > > 67.6% > > > > Are the numbers for 1) and 2) interesting enough to do something in this > direction? > > Surprising that the 7zip gzip compression is not more well known, it is > available since serveal years as advancecomp. > (i just looked it up and i used to 2004 to reduce the live filesystem size of > knoppix) > > Afaik the difference is that is tries out a few parameters for each junk and > uses the best one. > > It would be nice if you could try out something else: > decompress all *.gz files in the data.tar and compress the .tar with xz, > this could possibly yield better compression due to the big directory size of > lzma. > (after extraction the file would have to be gziped... but nevertheless it > would > be interesting) > > Christian > > -- > Christian Leber <[email protected]> or <[email protected]> > > > -- > To UNSUBSCRIBE, email to [email protected] > with a subject of "unsubscribe". Trouble? Contact [email protected] > Archive: http://lists.debian.org/[email protected] > > > > -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected] Archive: http://lists.debian.org/[email protected]
