如何卸载Windows Live Messenger

     最近想卸载MSN，但发现控制面板里得添加删除程序无法卸载MSN2009。下面介绍微软隐藏的方法来卸载：

1. 打开注册表，搜索“Windows Live Messenger”
2. 大概会在“HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\UserData\S-1-5-18\Products\（一堆数字）\InstallProperties”下，找到一个叫做“ModifyPath”的项，并拷贝该项的键值，大致像“MsiExec.exe /X{A9D94100-37D6-4D7B-A795-BD050BA9602B}”
3. 使用win键＋R，粘贴刚才拷贝的键值，运行
4. 按照提示，就能完全卸载MSN

WordPress with internal server error on 1and1 hosting

     For some reason, wordpress will always display “Error 500 – internal server error” for some PHP pages. My webhosting is on 1and1, so somehow the setting of PHP server is not correct.
Finally, got a solution and it works:

Modify the file .htaccess on the root directory:

1. Add the code following at top of .htaccess:
   AddType x-mapp-php5 .php
2. Changing:
   RewriteEngine on
   to:
   RewriteEngine ON

     Save the file, upload to the server. Here you go.

ORACLE databse can not start by missing tablespace file

     Today, as usual, trying to login to Oracle database do something, but when typing “sqlplus” and username/password, it showing:

     It seems like Oracle database was not starting somehow. After connect the database as SYSDBA, type some command for trying to restart the datadase:

     Now finally realized what happened and how this happened. There is a tablespace file “XXX.dbf” missing. To solve this issue, connect database as SYSDBA, then:

Create tablespace on NFS based LINUX + Oracle

     When the first time to create tablespace on SQLplus, it shows:

“ORA-27040: file create error, unable to create file. Linux-x86_64 Error: 13: Permission denied”

So I just change my home directory to “777”, then getting the error

“ORA-27054: NFS file system where the file is created or resides is not mounted with correct options”

     After check the “autofs” settings, I found the content of file “auto.home” has problem which is something wrong with NFS mount options. The solutions is change the original content

* -fstype=nfs,soft,intr,rsize=8192,wsize=8192,nosuid,tcp oracle.server.com:/users/&

to

* -rw,bg,hard,intr,rsize=32768,wsize=32768,suid,nfsver=3,tcp oracle.server.com:/users/&

SSH + X11 display after su to another user

     Sometimes we need to run the X11 application window via SSH. For example, I am user “A”, and SSH to host “example”. To be possible running X11 application window, we need to type the command:

#ssh -Y A@example

     In addition to the SSH restriction, we need to run an X application as someone other than yourself. For example, the Virtualbox can be only run by user “B”. If the user “A” can sudo to become user “B” or “A” is the root, in order to allow user “B” access to user “A”’s display, B needs to import “A”’s .Xauthority cookie. We can use xauth to accomplish this and it’s a quick one-liner before sudo su - B:

     A@example:~#xauth extract – :`echo $DISPLAY |awk -F: ‘{print $2}’` | sudo su – B -c “/usr/bin/xauth merge -”
     A@example:~#sudo su – B
     B@example:~#VirtualBox &