Virtualization technology - part1

It is long time I haven't update my tech blog. Recently I moved to new challenge job for IT service consultant. And work very hard to study and compare existing virtualization product, like VMware vSphere, Citrix XenServer and Microsoft Hyper-V.
I have a little experience to use Citrix Xenserver before work for this new company. The main reason to use Citrix Xenserver is that it provides free edition version for normal feature, so I use this to see what it can do for server management.

After studying the VMware vSphere key feature like vMotion, SvMotion, HA, FT, DRS, VDR, etc.., I really realize the business continuity is so many important for company.

Now I start to evaluate such feature by my Mac pro, and use VMware fusion as VM environment to install ESX, vCenter, Openfiler to simulate the real architecture like enterprise environment. It is so excited to try such feature.

Now I also understand Virtualization is not equal Cloud, but many Public Cloud use virtualization technology to build up the infrastructure. For example: Amozon EC2 use Xen, Chunghwa Telecom HiCloud use VMware. Using Virtualization technology to deployment server farms is very simple and easy, and can provide small to middle enterprise continuity server service with SLA. Why I said small to middle enterprise? Since virtualization is to run several guest OSs in one real Host, the main reason is software limitation, so the usage will not reach the hardware limitation when you only run one OS. You can check the detail link here.
The easy way to optimize the full hardware is to run several OSs in one hardware, so the virtualization technology is the right solution for this situation.

Finally the most important key point is you must estimate your existing application needs how many resources(CPU, Memory, DiskIO, Network traffic) when you want to move it into virtualizaiton environment. So the next task I will plan to build up a standard procedure to monitor existing application server and write some script to test the benchmark value when it reach some peak concurrent user. The value is very important when you want to know actual CTO/ROI.
And what is the next step when one VM is not enough to serve large peak connection. If your server need to scale up, this need more investigating to understand where is the bottleneck. I won't say too much here, may create another log next time. Here my simple suggestion is to use load balancer in the front end if the bottleneck is at web server side.

I also know another open source solution called Hadoop which you can use low cost hardware to  build up Cloud computing, storage. By using this technology you need to rewrite your application  by MapReduce API, it may be a lot cost to migrate your application. It would be a different topic to discuss in my planning.

Remote debug Android by adb tool

The default Android adbd is only listened on 127.0.0.1:5037, so if the USB is not working on developing board, you can't use adb to do something.

The default setting on device, only listen 127.0.0.1:5037


# netstat      
Proto Recv-Q Send-Q Local Address          Foreign Address        State
tcp        0      0 127.0.0.1:5037         0.0.0.0:*              LISTEN
tcp        0      0 192.168.1.128:56559    74.125.47.109:993      ESTABLISHED


Following is the step to enable the remote adbd

# mv /dev/android_adb /dev/android_adb.bk
# setprop persist.service.adb.enable 1
# setprop service.adb.root 1
# setprop ctl.stop adbd
# setprop ctl.start adbd
# netstat

Proto Recv-Q Send-Q Local Address          Foreign Address        State
tcp        0      0 127.0.0.1:5037         0.0.0.0:*              LISTEN
tcp        0      0 0.0.0.0:5555           0.0.0.0:*              LISTEN
tcp        0      0 192.168.1.128:56559    74.125.47.109:993      ESTABLISHED


The Host machine which want to connect to remote Android device, you can use following command:
Ubuntu$export ADBHOST=192.168.1.128
Ubuntu$./adb kill-server
Ubuntu$./adb devices
Ubuntu$./adb shell

Android source build problem on Virtual machine

You may install Ubuntu on Virtualbox, and use it to build Android source. When you build whole source code based on Android 1.6, you will not meet "too many open file" error when trying to build it. But when you run "repo sync" to update Android 1.6 to 2.1, you may meet this error.
This is caused by the small open file limitation on Ubuntu Linux system.
You can add following value into configuration file in /etc/security/limits.conf


jacky soft nofile 2048
jacky hard nofile 4096

This changing will let the user(jacky) can open files up to 4096.

Then the "too many open file" error will go out.

QQPinyin for Windows Mobile 6.5

Finally I found this great Pinyin input tool which can work fine on HTC Touchpro2 English ROM.
But first you must have chinese font installed in system, you can refer this link.
Although it is developed by China, but it also support BIG5 display by changing the default setting.
This is great tool which can work in pure English phone. I think this may help whom want to read/write chinese language in pure English Windows phone.

Howto: Build Android source on Ubuntu 9.10 need java 1.5

Now the java version on Ubuntu 9.10 is default as 1.6, but this version have problem to build Android.

The reason is mentioned in Android geting source page.

Following is a note from Internet to force install java 1.5.

My work Record: ubuntu 9.10 , build android , java 1.5

Android fontpack can be used on Windows Mobile 6.5

For some reason, I only can have Windows Mobile 6.5 english ROM for HTC Touchpro2 device.
I know there is a project called - Little bear studio(小熊工作室) which support chinese input method and chinese font for pure english Windows mobile device. But many people complain there are some issues on Windows Mobile 6.5, so I don't want to take a risk on my device. I look for a while from Internet, and some people suggest to use Android fontpacks which include Traditional/Simplied  chinese, Korea, Japenese font. Since I don't really need chinese input method on mobile, so I decide to install this package. (EVO Droid.zip). It works very well on my english Windows Mobile. It really can show chinese char when using browser, Outlook mobile, etc..
Hope you can enjoy this when you have same environment as me.

HowTo: Create a list of installed packages - Ubuntu Forums

HowTo: Create a list of installed packages - Ubuntu Forums

Recently, I have three Ubuntu host to develop something, but I always have to reinstall the necessary packages one by one when build system complain it needs some files.

Now I found a good solution to get the whole installed list and feed it to a fresh host, then I have some developing environment on three machine.

This is a great tip for me.

#dpkg --get-selections > installed-software (run on ready developing machine)

#dpkg --set-selections < installed-software (run on fresh machine, then followed by dselect)