network interface booting sequence

Network technologies have advanced a lot. Cross UTP cable is just so ancient. I just knew that cross cable is not necessary to connect two computers via UTP cable directly. Plug it, set the network, and voila done.

However when there is a service that bind to the network address, a chaos occurs. Since the cable only powered when both the computer up, to establish client server set up, we must turn the client first and then the server. Thus when the service in the server up, it detects that network is already up, and set up the networking accordingly. My experience with the setup was with postgresql. When the server up, but without internet connection, the service will be up without support to the inactive network interface. Only after the connection is up and the postgresql is restarted, the service is correctly set up.

This problem can be easily tackled by adding a network device such as a hub. However turning on the client first will also do.

That is if we work with LAN, what about WLAN? To be frankly, I have no idea. WLAN controllers software often work in GUI level. Yes, you can definitely set it up on lower level. Meanwhile services usually boot first, so it must be trickier to arrange the sequence. I think it must be easier to plug a LAN cable to an infrastructure, and let the clients connect there :).

useeTV telkom di linux

Jika anda menemui masalah waktu streaming useeTV dari telkom speedy di linux, solusinya mungkin install saja vlc plugin. Di debian:
mozilla-plugin-vlc - multimedia plugin for web browsers based on VLC

Canon SLR bad build quality

Ok, I  am really dissappointed with Canon SLR build quality, particularly regarding its anticipation against humidity and fungus. Yes I admit that I probably was clumsy,  putting the equipment in inappropriate place.

The problem is that the fungus appears below the the UV-IR filter instead of upon it. So you have to dissamble the entire camera to clean it up!

Let me simply explain where the UV-IR filter..
so if you remove the lens and lock the mirror up, you should see the 'sensor', actually it is the UV-IR filter. It's a kind of sensor compartment where the UV-IR filter is the outmost layer. Beneath it there is empty space, bayer filter and then finally the sensor.


Yup the fungus is under that UV-IR filter, between UV-IR filter and bayer filter. Why didn't Canon seal this sensor compartment so it is air-tight and there's no chance a single spore infiltrates inside? Why Canon, why?

Conclusion: in a humid region Canon SLR is apparently not an option.

Problems with browser client side ssl certificate in Linux

I tried to configure client side ssl certificate in debian squeeze using firefox and chrome (iceweasel as well). It was painful, did not work out.

Finally I tried Opera, voila.... it worked. Viva Opera!!!

However somehow I got problem when downloading Opera Browser from it front page, thankfully "tar.gz" keyword pointed me to opera repository :D.

setting group in linux for printer administration

Finally I need to learn this matter when I encounter the problem of giving right to ordinary user to touch the printing system administration, namely lpadmin. So here are important commands:
Shows available groups:

$ groups 

Shows groups where a username belong to:

$ id username 

Adds a user into a certain (secondary) group:

$ usermod -a -G group user 

warning: DO NOT forget the -a option. Putting only -G will delete other previously defined groups of the user, and overridden only with the new one. About the primary group check this link about the problem of primary group in debian.

Here is the complete commands with username latihan:

$ id latihan
uid=1001(latihan) gid=1001(latihan) groups=1001(latihan)

$ sudo usermod -a -G lpadmin latihan
$ id latihan
uid=1001(latihan) gid=1001(latihan) groups=1001(latihan),107(lpadmin)

Now user latihan can run lprm to delete print spools.

laptop processor fan error solved

Followed up the first failed attempt to disassembling my laptop, finally I could fix the fan error. My friend actually did it :D, just by spraying high pressure lubricant into the fan motor. I also renewed the thermal paste that was totally dried.

At a slight sight my friend was able to determine the problem. He turned the fan, but it didn't spin continuously, only 1 rotation and stop. After the lubricant was sprayed, it spin longer up to several rotation. Incredible skill. Good bye noise!

error in primary group changing of debian

There is terrible problem with primary group changing in debian. When I unleashed this code

sudo usermod -g primgroup user

the shell doesn't respond. It looks like that it hangs. But when I tried on other shell, it says that it change nothing (so apparently the first command [the hang one worked]). Still it is a mistery! Furthermore when I tried to create a file, and check it using

 ls -l 

it still gave me the old primary group. Amazingly after I restart my computer, tadaaa, everything set up as expected. So? I don't know