Changing dpkg-deb default compression from gzip to lzma for Hardy

[Thilo Six]

Kristian Erik Hermansen wrote the following on 17.12.2007 23:56
> We are talking about a 10x increase in the time it takes to create
> DEBs if moving from gz -> lzma.  Is this acceptable?

deb creation aka compression shouldn´t bother us as much as installing aka
extraction.
buildds should have enough power for that (given ubuntu delivers only for
"fast" architectures)


> Also, it is more
> than doubling the work placed on the installer's CPU.  

also note the package size went down from

gz: 39084	real    0m14.278s
to
7z: 27358	real    2m23.783s

which means ~30% less download time during a security update, which in turn
means ~30% less cost for that update.

currently i am on a 384kbit/s line.


comparation of a whole install (download time + extract time):

download time gz (39084/384)= 101.78s +  14.278s = 116.06s
download time 7z (27358/384)=  71.24s + 143.783s = 215.02s


So i think it depends on the goal we would like to reach:
 1. less package size = less time spending downloading
 2. cpu cycles = compress/extract time (both buildd and user pc)

depending on who you ask i think the answer will be quite different.
Someone on a modem line will much appreciate the 30% less time downloading
(7z), someone with a fat DSL cable and weak cpu will tend to prefer gz.

</snip>


-- 
Thilo

key: 0x4A411E09