Snow Leopard Server: Booting Up With 32 or 64 Bit Kernel

Snow Leopard Server (SLS) has built in 32-bit and 64-bit kernel. You can choose to boot up with 32 or 64 bit kernel by using the following two methods.

Method 1:

• Booting up your Mac and holding "6" and "4" key, the server will boot up with 64-bit kernel.
• Booting up your Mac and holding "3" and "2" key, the server will boot up with 32-bit kernel.

Your Mac will revert to the default kernel (32-bit) next time you boot up.

Method 2:

• The following command will change the default kernel to 64-bit.

sudo systemsetup -setkernelbootarchitecture x86_64

• The following command will change the default kernel to 32-bit.

sudo systemsetup -setkernelbootarchitecture i386

This method will change the default boot kernel and will take effect every time when start up.

Forget Ubunto login password

What to do when you forget the login password in Ubuntu

Root privilege is required to reset the password. But in generally, Ubuntu not allow you to login as a root. You can use recovery boot to get the root privilege using the following steps.

1. Reboot the computer.
2. In Grub boot menu, press "e" key. If the menu was not show defaultly, press "ESC" when booting will go to Grub boot menu if your system is pre 9.10 or hold "SHIFT" key when booting will invoke the menu if the system is 9.10 or after.
3. In boot menu, select recovery mode.
4. After boot up, it will show some options, select "root prompt"
5. Now you will get a shell with root privilege, use passwd "username" to reset the password.

Adjust Eclipse java heap size

Enlarge the java heap size to improve the performance of Eclipse.
Edit the file eclipse.ini under the folder of Eclipse.

Modify:

-XX:PermSize=256M
-XX:MaxPermSize=256M

to:

-XX:PermSize=256M
-XX:MaxPermSize=512M


Enable New Lenovo ThinkPad USB Keyboard with Trackpoint on Ubuntu 9.10

How to enable the middle key scrolling function of Lenovo ThinkPad USB Keyboard with Trackpoint on Ubuntu 9.10?

Add a file named mouse-wheel.fdi at /etc/hal/fdi/policy/ with the following content.


<match key="info.product" string="Lite-On Technology Corp. ThinkPad USB Keyboard>
<merge key="input.x11_options.EmulateWheel" type="string">true</merge>
<merge key="input.x11_options.EmulateWheelButton" type="string">2</merge>
<merge key="input.x11_options.YAxisMapping" type="string">4 5</merge>
<merge key="input.x11_options.XAxisMapping" type="string">6 7</merge>
<merge key="input.x11_options.Emulate3Buttons" type="string">true</merge>
<merge key="input.x11_options.EmulateWheelTimeout" type="string">200</merge>
</match>


Restart the computer!

cisco vpn

/opt/cisco/vpn/bin/

vpn connect [host] user [username]

Firefox add-ons

DOM Inspector
Firebug
Foxmarks(xmarks)
TwitterFox
User Agent Switcher
Web Developer
New Tong Wen Tang

Trash can

Location of Ubuntu's trash can.
~/.local/share/Trash

Notes about setting up a vnc server and account

How to set up a vnc server and account

first you have to create a linux account for the user.
And than edit /etc/sysconfig/vncservers to add a server for the user.
Don't forget to open a port in iptables for vnc remote login.
The must important is, the user have to login by ssh to reset the vnc password before login by vnc.
Setting vnc password will create a .vnc directory and set up some vnc environment configures.

Now, you can login by vnc.

BUT, while login by vnc, users may found they are in a "twm" desktop style.
It's a little ugly and not so esay to use.
If you want to login in a normal desktop, editing ~/.vnc/xstartup.
Add two lines into the file.

unset SESSION_MANAGER
exec /etc/X11/xinit/xinitrc

This can give you login in normal desktop.

在ubuntu中使用trackpoint的中間滾輪功能

Section “InputDevice”
Identifier “Configured Mouse”
Driver “mouse”
Option “CorePointer”
Option “Device” “/dev/input/mice”
Option “Protocol” “ImPS/2″
Option “Emulate3Buttons” “true”
Option “ZAxisMapping” “4 5″
Option “EmulateWheel” “true” < == add this line
Option “EmulateWheelButton” “2″ <== add this line
EndSection

Configure gnome on ubuntu

Add trash can on the desktop

1. run gconf-editor
2. apps/nautilus/
3. set trash_icon_visible as true

Android Programming Tutorial

Android程式設計入門: http://blogoscoped.com/archive/2007-11-19-n27.html
Android論壇: http://www.anddev.org/index.php
我的第一支Android程式: http://blog.bumblemachine.com/archives/15

Install/Update JDK on Linux

• sh jdk-6u7-linux-i586-rpm.bin

• alternatives --install /usr/java/jdk1.6.0_07/bin/java java /usr/java/latest/bin/java 2

• alternatives --config java

使用yum更新、安裝或刪除套件

yum為redhat及fedora之中的套件維護程式。
可幫助使用者執行套件的更新、安裝及刪除等等。
並會自動處理相依性的問題。
其設定檔位於/etc/yum.conf

• yum update [套件名稱]: 更新套件
• yum update: 更新系統中所有套件
• yum search [套件名稱]: 搜尋套件
• yum install [套件名稱]: 安裝套件
• yum remove [套件名稱]: 刪除套件
• yum clean: 清除/var/cache/yum之中的套件暫存檔
• yum clean all: 清除/var/cache/yum之中的所有套件暫存檔
• yum list updates: 列出可更新的套件
• yum list installed: 列出已安裝的套件
  

Clustering

Try more clustering size
Taipei: 128(96), 64(192), 32(384), 16(768), 8(1530)
Random: 128(72), 64(144), 32(288), 16(576), 8(1152)

Path View

Path queries can be serviced by direct lookup of the path view rather than computing paths on-the-fly.

Disk I/O

重新計算Random Map的SPC-64分割
計算Kaohsiung的SPC-96分割

如何定義disk I/O的行為以反應磁碟運作的真實狀況
如何定義page I/O策略以反應Buffer運作的真實狀況

Data-Broadcasting

• Packet size to tuning time conversion
• Packet size to latency conversion
  
• on-off times

Notes

• Dijkstra, HEPV in disk environment
• Disk Manager
• Page I/O Policy
  

在Linux中使用Trackpoint中間滾輪功能

1. 在/etc/X11/xorg.conf之中加入以下文字
2. Restart X
   

Section "InputDevice"
Identifier "Mouse0"
Driver "mouse"
Option "CorePointer"
Option "Device" "/dev/input/mice"
Option "Protocol" "ImPS/2"
Option "Emulate3Buttons" "on"
Option "Emulate3TimeOut" "50"
Option "EmulateWheel" "on"
Option "EmulateWheelTimeOut" "200"
Option "EmulateWheelButton" "2"
Option "YAxisMapping" "4 5"
Option "XAxisMapping" "6 7"
Option "ZAxisMapping" "4 5"
EndSection

mount

mount -t auto /dev/sda7 /mnt/vfat