Date: Sun, 19 Aug 2007 16:46:10 -0700 (PDT) From: Jeff Roberson <jroberson@chesapeake.net> To: freebsd-current@freebsd.org, d@delphij.net Subject: Re: Why we don't use bzip2 in sysinstall/rescue? Message-ID: <20070819163934.V568@10.0.0.1> In-Reply-To: <200708170939.l7H9diEk054469@lurza.secnetix.de> References: <200708170939.l7H9diEk054469@lurza.secnetix.de>
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This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --0-1647518475-1187567170=:568 Content-Type: TEXT/PLAIN; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE On Fri, 17 Aug 2007, Oliver Fromme wrote: > LI Xin wrote: > > As a side note. For networked installation, using bzip2 would reduce > > traffic by ~11%. > > And increase local installation time by 900% (except maybe > on high-end machines). > > I just tested extracting a 10 MB .bz2 file to /dev/null > on our 800 MHz server: It took 57 seconds. Recompressing > the result to .gz, extracting that took only 5 seconds. > The installation data is roughly 30 times that much. I tried this on my 1.8ghz pentium M laptop with 5.6MB of jpg data. I did: tar cvf foo.tar foo cat foo.tar >> /dev/null time bzip2/gzip foo.tar I removed and recreated the tar each time. The cat was to make sure it=20 was in cache, although it certainly was from the creation step before. Anyway, the results are: bzip2 2.452u 0.026s 0:07.65 32.2% 92+3227k 5+43io 0pf+0w 1849c/6w gzip 0.539u 0.020s 0:01.75 31.4% 109+3268k 2+44io 0pf+0w 493c/3w So only 4.6x slower here although my processor is twice as fast. Still, I= =20 imagine local installation is actually dominated by transfer rates from=20 the cd and file creation time on the new volume. Making lots of little=20 files is relatively slow, and I bet we don't use softupdates on the=20 target volume during sysinstall. A better test would be to actually=20 extract a bzip and a gzip from a cd to a local filesystem and=20 measure the times. I wouldn't rule it out just yet. Thanks, Jeff > > Best regards > Oliver > > --=20 > Oliver Fromme, secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing b. M. > Handelsregister: Registergericht Muenchen, HRA 74606, Gesch=E4ftsfuehrun= g: > secnetix Verwaltungsgesellsch. mbH, Handelsregister: Registergericht M=FC= n- > chen, HRB 125758, Gesch=E4ftsf=FChrer: Maik Bachmann, Olaf Erb, Ralf Geb= hart > > FreeBSD-Dienstleistungen, -Produkte und mehr: http://www.secnetix.de/bsd > > "... there are two ways of constructing a software design: One way > is to make it so simple that there are _obviously_ no deficiencies and > the other way is to make it so complicated that there are no _obvious_ > deficiencies." -- C.A.R. Hoare, ACM Turing Award Lecture, 1980 > _______________________________________________ > freebsd-current@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org= " > --0-1647518475-1187567170=:568--
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