Ubuntu hdparm APM and laptop mode tools
Ubuntu 8.10 is supposed to fix the apm=128 issue which causes high loading/unloading cycles for some hard drives; however, it is still BROKEN by default, here’s why:
the file 90-hdparm.sh located in various folders in /etc/acpi such as /etc/acpi/ac.d/, /etc/acpi/battery.d/, /etc/acpi/resume.d/, and /etc/acpi/start.d/ is supposed to fix the hdparm problem; however, notice the following lines:
DO_HDPARM=y
if [ -e /usr/sbin/laptop_mode ] ; then
LMT_CONTROL_HD_POWERMGMT=$(. /etc/laptop-mode/laptop-mode.conf && echo “$CONTROL_HD_POWERMGMT”)
if [ "$LMT_CONTROL_HD_POWERMGMT" != 0 ] ; then
# Laptop mode controls hdparm -B settings, we don’t.
DO_HDPARM=n
fi
fi
This checks if the file /usr/sbin/laptop_mode exists and if it exists, then it checks if CONTROL_HD_POWERMGMT in laptop-mode.conf is set to a non-zero number in order to determine if laptop mode is enabled. However, Ubuntu installs laptop-mode-tools by default, so /usr/sbin/laptop_mode always exist and that by itself does not tell whether laptop mode is on. Rather, ubuntu turns laptop mode off by default by setting the variable ENABLE_LAPTOP_MODE=false in /etc/default/acpi-support, but this variable is not used anywhere except in the init script /etc/init.d/laptop-mode from line 30 to 37:
# FIXME: this shouldn't be configured there
if [ -f /etc/default/acpi-support ]; then
. /etc/default/acpi-support;
fi
if [ x$ENABLE_LAPTOP_MODE = xfalse ]; then
exit 0;
fi
which stops the script from executing if the variable is set to false. One funny thing about this is that it says FIXME in the comment but it actually never get fixed even after Ubuntu 8.10 is released. With Ubuntu’s default settings laptop mode tool is supposed to be disabled by ENABLE_LAPTOP_MODE=false, but the script 90-hdparm.sh always thought that it is enabled as long as laptop mode is installed because /usr/sbin/laptop_mode is always there. It then checks the variable CONTROL_HD_POWERMGMT in /etc/laptop-mode/laptop-mode.conf, which is 1 by default, and it will set DO_HDPARM=n, thinking that laptop-mode is on and letting it to handle hard drive’s APM setting instead while actually laptop-mode is OFF and not taking care of the APM problem. This makes nobody changing the hard drive’s default APM setting from 128 to something else, leaving the clicking problem unsolved.
I did some workaround to 90-hdparm.sh by changing the line “if [ -e /usr/sbin/laptop_mode ] ; then” to “if [ -e /var/run/laptop-mode-tools/enabled ] ; then” in order to check if laptop mode tool is enabled, because whenever laptop mode tool is enabled, it creates the file /var/run/laptop-mode-tools/enabled, so I think this is the right way to check if it is actually enabled rather than just installed. I also think that the variable ENABLE_LAPTOP_MODE in /etc/default/acpi-support should be removed instead, just as Debian did in acpi-support version 1.109-5. That variable is just there to confuse people more and mess up the configurations. Even the comment in /etc/init.d/laptop-mode says “FIXME: this shouldn’t be configured there” already, why don’t they just fix it right now and make all these things less messy. I have tested Debian six months before and they really did a good job in fixing those hard drive clicking issues by making the 90-hdparm.sh file and removing the ENABLE_LAPTOP_MODE variable.
Wubi - Install Ubuntu inside Windows w/o Partitioning
If you want to install ubuntu 7.04 Feisty, but you don’t want to modify your Windows partition and you want to install it inside, Wubi is for you. According to its website:
Wubi is an unofficial Ubuntu installer for Windows users that will bring you into the Linux world with a few clicks. Wubi allows you to install and uninstall Ubuntu as any other application. If you heard about Linux and Ubuntu, if you wanted to try them but you were afraid, this is for you.
Moreover, Wubi doesn’t need you to replace the default Windows bootloader, as “Wubi adds an entry to the Windows boot menu which allows you to run Linux. Ubuntu is installed within a file in the windows file system (c:\wubi\disks\system.virtual.disk), this file is seen by Linux as a real hard disk.” Then it loads the file as a loopback root Filesystem, kind like those described in “The Loopback Root Filesystem HOWTO,” but with the loopback filesystem is actually in Windows’s partition.
Since Wubi makes Ubuntu run inside Windows partition, there will be a little bit performance penalty, especially when your Windows partition is fragmented. Moreover, if there were any error in the ntfs partition that affects the system virtual disk, you need to fix the errors with something like chkdsk in Windows first before booting Ubuntu. If you’re not afraid of partitioning, I still recommend you to install Ubuntu in a separate partition.
Some screenshots of the Wubi installer:
http://www.cutlersoftware.com/ubuntusetup/wubi/en-US/screenshots.html
Fix Linux Display Resolutions
Fix linux display resolutions when your xorg video resolutions are misread, causing display problems on boot like the one in the video, ie. it attempts to display a resolution higher than what your computer can support.
3D Desktop! TouchScreen and XGL on Linux
found in here
“I use: Gentoo linux, penmount usb touchscreen, XGL Gnome and my hands!!!!! Bill Barsch. Goiania-Goias”
I can’t post the google videos directly to wordpress from google, I had to copy and paste the code to post it here.
How to kill a hard drive in Linux quietly with an easy way to undo it
We know that we can kill Linux by running the command rm -rf /, but this can’t be undone as your files are gone. Here’s a quick way to make your hard drive look like formatted and how to undo that easily (tested under VMWare with ubuntu), click each picture for more information.
First back up the first 10000 bytes of the hard drive and then replace it with empty data.
Everything seemed to be OK and we could still shut down normally, but……..
After we restart, it won’t boot anymore with an empty MBR and all the partitions are gone! To fix it we need to boot from a boot disk and restore what we backed up.
After all this it everything worked again. Now restart and check it…
Inspiration from my very sad personal experience:
Once upon a time I thought the first 512 bytes of hda1(where my Windows is installed) is the MBR but in fact it’s supposed to be the first 512 bytes of hda, I ran the command “dd if=/dev/zero of=/dev/hda1 bs=512 count=1″ and thought this would reset the MBR, but the Windows partition is ruined instead!
Make Ubuntu Dapper to display Chinese well in two minutes
With Ubuntu Dapper you can make Linux to display Chinese fonts (or maybe for other languages as well) much much easier than before. After you read this you’ll find out to make Linux to display Chinese well can be as simple as this.
- Get the font Simsun.ttc from Windows or some other high quality Chinese fonts and put them in the folder /usr/share/fonts/truetype.
- Update the font cache by runing “sudo fc-cache -fv”.
- Last and not least run the command “sudo fontconfig-voodoo -f -s zh_CN” and you are done! restart X and check it out.
Here are some screenshots for the effects:
You can even see bold, italic, bold+italic fonts:
Firefox browsing Yahoo China:
Tips to test potentially unsafe software without hurting computer.
If you really want to test out or use a program that might be potentially unsafe, contain virus, or do something you didn’t expect, but you don’t want your computer to be hurt, what should you do? Here’s some tips to do it safely.
- for both Windows and Linux you can make a Windows virtual machine with VMware and make a snapshot before testing those programs, if something is wrong with the program you can go back to the snapshot.
- For linux users there’s even more options, we could test the program with a non-root user account, but still you might want to create a new user account to test it if your own user account has many datas because some programs might destroy datas that they can access.
- For advanced users they can use other options like make virtual machine with user-mode kernel or mount with unionfs to test the program with a virtual root account.
- For Windows users running programs with limited users might help, but most Windows programs won’t run properly under those accounts, for now the only solution that I can think of for this is VMware. You can also track what the program does by using Filemon to monitor file changes, Regmon to monitor registry changes, and Urlsnooper to monitor the url the program accessed, or any other utilities in addition of those mentioned above.
Colinux/Gnome with Mac OS like theme
Colinux/Gnome with Mac OS like theme. 
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Recommended Services:
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Others:
