An engineer's life around Kyoto

 I built and am running a mail server, using dovecot for IMAP4 server and Power DNS (pdns) for DNS authoritative server, and memcached for back-end service for some mail filter. I also use LXC for staging environment to test my mail server, but running those services is not straight forward. My understanding is that it is because some security features of systemd using Linux kernel namespace function conflict with the use of namespace in LXC container. So, if you want to run memcached, dovecot, and pdns via systemd within LXC container, you have to disable some security features of systemd by configuration. My additional configuration to systemd is as follows: root@myhost:/# cat /etc/systemd/system/memcached.service.d/99-ns.conf [Service] ProtectSystem = no ProtectHome = no PrivateDevices = no PrivateTmp = no cat /etc/systemd/system/dovecot.service.d/99-ns.conf [Service] ProtectSystem = no PrivateDevices = no PrivateTmp = no root@myhost:/# grep -v '#' /etc/systemd/system/pdns.s...

Figaro's Password Manager 2 was my favorite password management tool. It is GTK2-application to preserve and manage your pairs of ID and password secretly with cipher. To my regret, its Debian package was orphaned many years ago and I thought it was time to switch to another password management tool. But besides finding a good alternative choice, I had a big problem: migration. Figaro's Password Manager 2 does have data export function, but only in special XML format. If you want to move your data to a different application, you have to change the format of the data even if the application can import the data. As my next password management tool is KeePass2 or KeePassXC , I need a XML to CSV data converter. So, I have been developing the conversion tool very slowly and finally, completed. Today, I published it on GitHub , which I named fpm2_csv . The history of the code is quite embarrassing, but very few people in the world would be interested in it, that doesn't matte...

 On December 6, Debian 11 installer alpha 3 has been released. As I wanted to install Debian to my new laptop machine Panasonic CF-SV9, I tried it. The result: fine. Debian 11's Gnome desktop environment is running on my new machine now. I am keeping pre-isntalled Windows 10 pro, and the machine is  Windows and Linux dual booting machine. The installer seems matured, inspite of its version name. But there is one drawback remaining. The circular pad built-in is not working correctly inspite of xorg synaptics input device settings written in /etc/X11/xorg.conf. It may be caused that the graphic is now under control of wayland, in place of  Xorg server in my buster machine. If you want to follow me, please take care of Windows 10's  BitLocker. It will demand recovery key after your installation of Debian. Take some backups of the recovery key before hand.

When I'm home, I use fiber-optic line with a dedicated old small router (YAMAHA RT107e) for access to the Internet. But I recently became anxious about the router. If it fails, how can I survive until I get another one? So, I tried to connect my Debian desktop PC to the fiber-optic line without the router. The PC have to talk to the other side of the line with PPPoE but I did not know how. In my PC, the Network Manager manages network configuration. So, I had to configure the Network Manager to utilize the pppoe like : nmcli connection add ifname eth0 connection.type pppoe username USERNAME password PASSWORD

It's been a long time since my last post. Recently, I bought a secondhand Panasonic T7 laptop PC. It was as much as seven thousand yen (about 76 USD), and I am pleasant for the price. I installed Debian 7.1 (wheezy) to the PC and set up Xfce desktop environment. Most of the things went well, but the X-Window system didn't recognize automatically that its touch pad device was circle and able to sense tapping operations. I was disappointed a while, but managed to write additional configurations for the X server with a help of the man page of Synaptics touch pad input driver. For reminder,  here it is: $ cat /etc/X11/xorg.conf Section "InputClass"     Identifier  "MyTouchPad"     MatchDriver      "synaptics"     Option        "TapButton1" "1"     Option        "CircularPad" "true"     Option  ...

If you are an owner of a laptop PC running Linux, you might be annoyed with the battery shortage. If so, try consulting the command 'powertop'. It tells you what kind of background tasks  are consuming the electricity a lot. Cheers!

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...

I usually use the gdm for X session manager. Under this circumstance, I wanted to test a xdm, a very traditional X session manager. Rather than replacing gdm with xdm, I tried to start a xdm within a gdm session. Here is how I did: In a gnome-terminal type as follows: # su # xdm -server ":1 nest local /usr/bin/Xnest :1 -geometry 800x600" Cheers!

I am preparing for a presentation using X desktop, and want to start another gdm session inside my GNOME desktop environment. It seemed to require long descriptions in the configuration file at first, but  a simple command solved the problem. $ gdmflexiserver -n This starts another gdm greeter inside a  Xephyr (if unavailable, Xnest instead) window. Excellent!

Here is a tragic news from Japan. Japanese hosting provider Sakura Internet started its cloud service 'Sakura-no Cloud' last November. Unfortunately, after the serious performance depression in December, about ten percent of the virtual servers has lost its whole data in the end of the year 2011. They say one of the operators has done a wrong data shrinking operation while they struggled against the performance depression. I feel sorry for the owner of the lost virtual servers. At the same time, this accident makes me change the point of view at the cloud service. That is, you can't control this kind of risks behind the virtualized service. You've got to protect your data by yourself. Refrecence: The trouble report of Sakura Cloud around new year

I recently tried to set up Xen on my Squeeze box, with intel 945GM graphics controller. I followed the instruction on Xen - Debian Wiki . I installed the Xen hypervisor, kernel, xen-tools and other stuff, then created a domU image of Ubuntu natty. After that, I rebooted the system. But when X server was about to be launched, the screen became black out,  both keyboard and mouse don't work anymore. I reread the article on the wiki, and figured out the Xorg driver for Intel graphics controller  is suspicious. So, I changed the Xorg driver 'intel' to 'fbdev' wrting /etc/X11/xorg.conf , and rebooted.  This workaround works out! The drawback of the workaround is, 'intel' driver specific features, including DRI and XvMC, are disabled.

I have been a  Debian GNU/Linux user since 2007. Since then, I experienced several major OS upgrades (dist-upgrade).  But every time I dist-upgrade, some trouble annoyed me. The most recent problem was related to the seting of Xorg server. When starting up X server (from gdm3), the xserver process couldn't find the glx symbols. In the /var/log/Xorg.0.log: (EE) GLX error: Can not get required symbols. This prevented Compiz Fusion window manager from working on the X desktop. Although the hardware video driver was "intel", it seams that some extra glx code for Nvidia caused the trouble. The following command fixed the problem:   aptitude purge fglx-glx fglx-driver nvidia-vdpau-driver (I don't know which package was actually problematic.) If you have a glx related problem with the intel graphic controller chip, try removing unrelated packages that supposed be combined with nvidia or Radeon! That save you some (small amount of ) disk spaces :-) B...