On Sun, 2006-01-01 at 19:38 -0500, Franck Y wrote: > Hi everyone, > I ve got a strange behavior with bz2 and gzip. > When i compress a small folder around 225 Mo the compression goes to > 49 Mo for gzip > 46 mo for bzip2 > > When i compress a bigger folder around 5 Go the compression goes to > 2.6 Go for gzip > 3.1 mo for bzip2 > > > Bzip2 has a better compress for Small folder and gzip has a better one > for big folder. > Has anyone of you has the same effect. > > Maybe gzip did'nt compress everything how can i check this. > Should i be worried. > It's mostly office document. > Happy new year, It is really dependent upon what it is you are compressing. If you compress a bunch of files like text files with a lot of "empty" space inside them, you will get really good compression ratios. If you compress a bunch of files with compressed imaged (like PNG or JPG), then you won't get very good compression at all. On my system, I used gzip and bzip2 to compress /etc just as a test: [root@ml110 ~]# tar zcf etc.tgz /etc/ tar: Removing leading `/' from member names [root@ml110 ~]# tar jcf etc.tar.bz2 /etc/ tar: Removing leading `/' from member names [root@ml110 ~]# ls -lh etc.t* -rw-r--r-- 1 root root 6.0M Jan 1 18:49 etc.tar.bz2 -rw-r--r-- 1 root root 8.4M Jan 1 18:48 etc.tgz So on my systems, bzip2 beat the heck out of gzip. Thomas
