Author: admin

peter-dwarf can support 32 bits elf only

There is a western friend told me he can’t use peter-dwarf to parse his 64 bits elf file, after i trace my code, i finally found my peter-dwarf library only support 32 bits elf. I need some time to enhance it and make it 64 bits.


2013/04/26 2

something need to care when you use devstack

I have a ubuntu 12.10 64 bits, i can easily install devstack, but there are some points still need to care about the devstack 1. Devstack installation script is to git clone the latest version from the openstack source repository, if the repository’s code contain bug, your openstack will fail. If you use devstack in…
Read more


2013/04/24 1

steps to reinstall devstack

steps to reinstall devstack 1) Remove all the openstack;s databases from mysql, glance, keystone, nova, etc… 2) Delete the install directory of devstack, default is /opt/stack 3) Remove your old devstack git clone directory, because we want to check out the latest code 4) You *don’t* need to delete /usr/local/lib/python2.7/distpackages/openstack* , but if you did…
Read more


2013/04/22 4

let’s beat vSphere using openstack

Let’s beat vSphere using openstack, first step is to learn everything from it o VMware vSphere 5 Evaluation Guide – Volume1 VMware-vSphere-Evaluation-Guide-1 o VMware vSphere 5 Evaluation Guide – Volume 2 – Advance Storage Features VMware-vSphere-Evaluation-Guide-2-Advanced-Storage o VMware vSphere 5 Evaluation Guide – Volume 3 – Advance Networking Features VMware-vSphere-Evaluation-Guide-3-Advanced-Networking o VMware vSphere 5 Evaluation…
Read more


2013/04/17 0

A very professional ppt that talk about system performance tuning

A very professional ppt that talk about system performance tuning download : scalelinuxperformance-130224171331-phpapp01


2013/04/17 0

development openstack dashboard

I and my colleague are currently develop some modules on openstack dashboard. Here is the list for you to know : when you modify a page in dashboard, which files you need to deal with, this will save you some time: download : openstack_dashboard


2013/04/12 0

openstack – restart error : Max retries exceeded with url

If you install openstack by devstack, when you reboot your server and restart the openstack by this script http://www.scalegrid.net/blog/?p=52, when you browse to the dashboard and you will see this error message “HTTPConnectionPool(host=’192.168.100.170′, port=8776): Max retries exceeded with url: /v1/b721f5b1f7cd43dd83ee573f6d4e6c74/os-quota-sets/b721f5b1f7cd43dd83ee573f6d4e6c74 (Caused by <class ‘socket.error’>: [Errno 111] Connection refused)” You should check with your endpoints server…
Read more


2013/04/09 0

Openstack architecture diagram (kvm, qemu-kvm, libvirt, nova, cinder)a

Correct me if i am wrong. Openstack components (nova, cinder, glance) controls libvirt to provide visualization and libvirt use qemu-kvm as the hypervisor. The reason openstack don’t control the qemu-kvm directly is because libvirt provides better cross VM functionality (it can adopt to xen, vmware, etc…) and it provides high-end function such pool management and…
Read more


2013/03/29 0

put python+django to apache through virtualhost

to put python+django to apache through virtualhost 1) edit /etc/httpd/conf/httpd.conf 2) edit /root/workspace/MyDjangoProject/P1/wsgi.py, change it to


2013/03/26 0

error in manage.py createsuperuser

error in manage.py createsuperuser To solve the above issues, type in


2013/03/26 0

GDB will remove all breakpoint and set it back repeatly

When you set the breakpoint by input the “b” command, the gdb will not set it immediately, it will wait until the user pressed “c” to cont execute the program. After you pressed “c”, gdb will set all the breakpoints for you. The most funny thing is : when gdb hit a breakpoint and gain…
Read more


2013/03/23 0

qemu debug server hang after breakpoint is hit

If you are developing a debug server for qemu, after qemu hit a breakpoint, your server have to remove the breakpoint manually and re-insert it after the cpu passed that EIP, otherwise the cpu will forever stay in the EIP and can’t single-step/cont to the next instruction. If you take a look the gdbstub.c, gdb…
Read more


2013/03/21 0

QEMU migration via QMP / Monitor command

I just tested the qemu-kvm with QMP, when i send out the qmp command for migration, it takes 20 seconds, it is much slower than type in the command in qemu monitor.


2013/03/21 0

How to use QMP, send command remotely to qemu

To use qmp and send command to qemu from another process, start qemu by This will create a file /tmp/test.gmp for interchange the command. Then you can start another terminal and invoke command.txt: !!! remark, must invoke { “execute”: “qmp_capabilities” } before invoke any qmp command


2013/03/20 1

openstack conflict with virtualbox

When you are running vm in virtual box, and try to start any vm in openstack. The vm that are running in virtualbox will crash immediately, you need to do the follow command to shut it down. If you want to restart that VM, please rmmod the kvm module. I guess is that the kvm…
Read more


2013/03/17 0

OOM has trouble to KVM, it can’t shot down the kvm

In Linux, if the system is out of memory, OOM will pick one process to kill. But someone reported the OOM can’t kill the qemu-kvm, that mean if you are running many VMs that eat up all the memory, the Linux will hang because OOM can’t kill them In tried to run 64 VMs using…
Read more


2013/03/17 0

Restructuring the debugger

At the moment, i am facing 2 big problems of bochs, the first one is unsolvable, bochs running too slow. It is ok if you are doing a hobby OS development, but if you are trying to use bochs to run a full feature Linux kernel or a windows 7, it is just so slow.…
Read more


2013/03/13 0

qemu single step will fail if current EIP hit a breakpoint

I use the following code to insert a breakpoint in physical address 0x1600000 qemu successfully hit the breakpoint and stop, then i try to single-step by the following code: Nothing happened, the EIP still stay in 0x1600000, but if i delete the breakpoint, the single step just work again. Am I missed something?


2013/02/14 0

when you debugging qemu, it will keep firing SIGUSR1 so gdb will always catched in some breakpooints that are not defined by you

when you debugging qemu, it will keep firing SIGUSR1 so gdb will always catched in some breakpooints that are not defined by you, to turn off the SIGUSR1, you have to: (gdb) info signal SIGUSR1 Signal Stop Print Pass to program Description SIGUSR1 Yes Yes Yes User defined signal 1 And if deemed to not…
Read more


2013/02/12 0

linker script offset seems crazy

linker script offset seems crazy, take a look the following two pictures  


2013/02/09 0

compile grub2 : error: ‘gets’ undeclared here

if you compile grub2 , you may get “error: ‘gets’ undeclared here yum”, to fix it, run the following command: sed -i -e ‘/gets is a security/d’ grub-core/gnulib/stdio.in.h  


2013/02/09 0

compile 64 bits newlib on 64 bits linux host

If you compile newlib in x86-64 host and want to have 64-bits newlib, you have to add “–disable-multilib“, otherwise you will get the following error:


2013/02/03 0

PSI probe for tomcat can’t generate chart

Add this “CATALINA_OPTS=-Djava.awt.headless=true” to catalina.sh


2013/01/31 0

newlib compile error in Fedora 18 64 bits

when you meet the following error, add “.code32” can fix it. ../../../../../../newlib-1.19.0/newlib/libc/machine/i386/memcmp.S: Assembler messages: ../../../../../../newlib-1.19.0/newlib/libc/machine/i386/memcmp.S:18: Error: invalid instruction suffix for `push’ ../../../../../../newlib-1.19.0/newlib/libc/machine/i386/memcmp.S:21: Error: invalid instruction suffix for `push’ ../../../../../../newlib-1.19.0/newlib/libc/machine/i386/memcmp.S:22: Error: invalid instruction suffix for `push’ ../../../../../../newlib-1.19.0/newlib/libc/machine/i386/memcmp.S:23: Error: invalid instruction suffix for `push’ ../../../../../../newlib-1.19.0/newlib/libc/machine/i386/memcmp.S:72: Error: invalid instruction suffix for `pop’ ../../../../../../newlib-1.19.0/newlib/libc/machine/i386/memcmp.S:73: Error: invalid instruction suffix for…
Read more


2013/01/30 0

10 places where anyone can learn to code

Teens, tweens and kids are often referred to as “digital natives.” Having grown up with the Internet, smartphones and tablets, they’re often extraordinarily adept at interacting with digital technology. But Mitch Resnick, who spoke at TEDxBeaconStreet in November, is skeptical of this descriptor. Sure, young people can text and chat and play games, he says, “but that…
Read more


2013/01/30 1

In search of the anti-ddos device

http://dev.esl.eu/blog/2010/09/10/in-search-of-the-anti-ddos-device/ Preamble The following text describes the evaluation of the most reasonable solution in order to achieve the goal of protecting our infrastructure from DDoS attacks. All collected values and impressions do not lay claim to being correct nor complete. This article only reflects our experiences and data and therefore should be used to help…
Read more


2013/01/21 0

Fix the PermGen error in tomcat

Fix the PermGen error in tomcat, execute this before startup.sh: export JAVA_OPTS=”-XX:PermSize=2048m”


2013/01/15 0

Ported ubuntu theme to fedora

Ported ubuntu theme to fedora, tested on FC17, unzip themes.tar.bz2 in /usr/share/themes


2013/01/04 0

A x86 java disassembler from Maxine Project

I have been asking for a java x86 disassembler library for a long time, i finally found “Maxine” project from oracle, it is a VM project with built-in a x86 assembler written Java. I git-ed the source and compile them in eclipse, it works!, here is the source and screenshot. source : maxine_disassembler


2012/12/27 0

Lowest 7 levels of /lib, /bin, /usr/bin, /usr/lib

No recursive /bin /lib /usr/bin /usr/lib


2012/12/24 0

How to change Fedora’s font rendering to get an Ubuntu-like result

Font rendering is a matter of taste. However, I personally think Ubuntu’s default font rendering is the most eye-pleasing one of the whole Linux eco-system. And if a website’s CSS font stack is looking good on Ubuntu, you can be relatively sure that it also works for Mac or MS Windows as long as the used fonts are available on these…
Read more


2012/12/13 4

qemu-kvm’s library dependencies

chrome’s library dependencies


2012/12/11 0

chrome’s library dependencies

chrome’s library dependencies


2012/12/11 0

The way i compile elfutils

autoheader aclocal -I m4 autoconf automake -a -c ./configure make


2012/12/10 0

my .vimrc


2012/12/10 0

get out of the keying trouble when you start chrome in fedora 17

just add “–password-store=basic” in the option you start chrome.


2012/12/09 0

A great qemu development link

http://people.cs.nctu.edu.tw/~chenwj/dokuwiki/doku.php?id=qemu


2012/12/07 0

Filter out special character in json

$str=”`!@#$%^&*()_+[]\{}|;’:\”,./?”; $str=str_replace(“\\”,”\\\\”, $str); $str=str_replace(“\””,”\\\””, $str);


2012/11/29 0