An engineer's life around Kyoto

Recently, I have written an article about how to make a chroot login environment for each user in the diskspace-saving way. It is for Kansai Debian meeting , and I'm going to give a presentation  based on the article there on Feburary 26th. The article is written in Japanese. Its title is "Building a multi-user environment with autofs and pam_chroot". Another effort is needed to translated it into English. If anyone wants it, please give me a comment. :-)

 7-zip is a popular compression tool and  famous for high compression ratio. But unfortunately, there is no description in the man pages about switching the compression algorithm to PPMd . Actually, PPMd provides very high compression ratio with lower CPU power consumption with a text data, and I would like to show its efficiency. Here is an example. Below is a comparison of size and CPU time between variety of  compression methods .    command       size      time    7z a -tzip -mx=9    3699 bytes   0m0.410s 7z a -tgzip -mx=9    3610 bytes   0m0.411s 7z a -tbzip2 -mx=9    3363 bytes    0m0.608s 7z a -m0=lzma -mx=9    3406  bytes   0m0.109s 7z a -m0=PPMd -mx=9    2699 bytes   0m0.058s The original file is a 6795 byte text file. As you can see, efficiency of PPMd is outstanding! PPMd helps me a lot to compact log files.