An I/O Performance Comparison Between loopback Backed and blktap Backed Xen File-backed VBD

I have done some I/O performance benchmark test of Xen DomU. For easier management, some of our DomU VMs are using file-backed VBDs. Previously, our VMs are using Loopback-mounted file-backed VBDs. But blktap-based support are recommended by Xen community. Before considering changing from loopback based VBD to blktap based VBD, I have done this performance […]

lftp Disable SSL

lftp some times stalls with message “Making data connection” when “ls” the directory after logged in the ftp site. The message may appear like this: < — 227 Entering Passive Mode (xx,xx,xx,xx,xx,xx) —- Connecting data socket to (yy,yy,yy,yy) port zz `ls’ at 0 [Making data connection…] But some client such as filezilla may works on […]

How to Duplicate Xen DomU Virtual Machines

Assumption: There are VBD based Xen DomU virtual machines stored under /lhome/xen/vm-f11-sample/. There are two files under vm-f11-sample: (The configuration file) and vmdisk0 (The virtual disk). Now we want to duplicate the virtual machine vm0 stored under vm-f11-sample to vm- which is stored under vm- And vm-’s ip will be The steps to […]

A Simple CPU and Memory Performance Test of Xen Dom0 and DomU

Please refer to Setting Up Xen Dom0 on Fedora : Xen 3.4.1 with Linux Kernel 2.6.29 on Fedora 12 for the platform of this test (this test runs on Fedora 11, however). I have done some simple performance test on DomU and Dom0 and compare with the performance on physical machines. These test are simple, […]


mplayer 使用中文字幕文件时经常会出现乱码问题. 以下是解决办法: 1. 外挂字体方法 比如当前目录下有文件为Gone with the Wind.avi, 字幕文件为: 可以使用如下命令来播放, 将不会出现中文字幕乱码的问题了: mplayer -ass -subcp cp936 Gone with the Wind.avi -sub 对于以上参数的解释: -ass: Turn on SSA/ASS subtitle rendering. With this option, libass will be used for SSA/ASS external subtitles and Matroska tracks. You may also want to use -embeddedfonts. NOTE: Unlike normal OSD, […]

Vim Removing “^M” Returns from Files

When editing some files fro Windows in vim, there are some ugly “^M” returns. Here is a method to remove and replace these “^M”s (please note that you should not copy/past to use the follows): :1,$s/{Ctrl+V}{Ctrl+M}//{Enter} {Ctrl+V} means keyboard operation that is push ‘ctrl’ and ‘v’ together. {Enter} is push ‘enter’. : means that it […]

My Vim Emacs and Other Configuration Files

My .vimrc .emacc files can be downloaded from here: My text editors are especially configured for source code such as C/C++/shell editing. I prefer to use spaces instead of tab. And my favourite tab size is 4. Some vimrc parameters and the comments are listed here. Details and the updated configuration files please refer […]

Fedora 中文字体设置

Fedora 一直有中文字体难看的问题, 尤其是在英文环境中. 使用本文中的配置方法可以得到令人满意的中文效果. 此方案中使用字体都为开源且在Fedora源中自带. 此方案对 Fedora 9 – 20 有效. 对于后续版本支持我会确认并更新此文章. 此方案对Gnome, KDE都有效. Firefox 中也有中文难看的问题, 后面会提到. 快速配置方法 如果你想马上配置好,请使用如下命令。此方法测试使用效果良好。 # yum install cjkuni-ukai-fonts cjkuni-uming-fonts # wget \ -O /etc/fonts/local.conf 相关英文字体配置可以参考:Improving Fedora Font Rendering with Open Software and Fonts Only. Fedora 系统中文字体的配置方案 使用uming和ukai字体,即AR PL UMing CN等. 中文字体和等宽字体效果如图所示(点击看大图, Firefox 中文字体设置在后面会提到). 方法如下: 安装字体 首先安装这两个字体: cjkuni-ukai-fonts cjkuni-uming-fonts (在Fedora […]

Installing NVIDIA Driver in Fedora

Using rpmfusion’s rpm packages to install NVIDIA driver in Fedora is introduced in this post. First, check the proper drivers for the card on [1]. 1. Add rpmfusion. Enable RPM Fusion repositories 2. Install the driver # yum install kmod-nvidia xorg-x11-drv-nvidia The reboot system. 3. Edit /etc/X11/xorg.conf # nvidia-xconfig The nouveau module conflicts with the […]

Compiz-fusion on Fedora

1. Install relevant packages #yum install ccsm emerald-themes compizconfig-backend-gconf fusion-icon-gtk emerald compiz-fusion compiz-fusion-gnome libcompizconfig compiz-gnome compiz-bcop compiz compizconfig-python compiz-fusion-extras compiz-fusion-extras-gnome 2. Start compiz-fusion by using command “fusion-icon”. It can be found in “Applications -> system tools -> fusion-icon”. It will be more convenient if “fusion-icon” is added to autostart list by adding a entry in […]

ALSA Problem of Fedora 11 on Compaq Presario CQ35-240TX

When I get my new Compaq Presario CQ35-240TX, of course, the first thing is to install Fedora ;) But unfortunately, after installation there is no sound! It seems there is something wrong with the driver configuration. Here is a solution to this: Add these two line at the end of /etc/modprobe.d/dist.conf options snd-hda-intel model=hp-m4 enable=1 […]