Wu's Blog

It’s about 5 years since last time I visited Chengdu. A beautiful city, people say “you gonna love it, and wanna live there if you come to Chengdu”. People looks like live very relax in Chengdu, they drink tea in park, play Mahjong and enjoy professional people scrape their ears (most like ears massage). I was being Chengdu for 3 month, so I’m kind familiar with this city. All memory is 5 years ago. I was excited to get my Raspberry Pi on morning, I plan to play on it all the day. But my wife wants to discuss travel plan when we had lunch. She told me she visited Chengdu several times before, but no one is real travel, they just went to the city, got goods, then went back, she only know one place “He Hua Chi” – a clothes market. They bought clothes there and sales in their city. Finally, we had a 3 days trip in Chengdu! That’s a crazy plan for me since I never tried planning and going in same day! We flight to Chengdu on night, and checked in a great hotel. Since it’s close to Chinese

Storage is critical component for virtualization, lot of VM performance issue is related to storage latency. You may see similar error message on vmkernel log for some case: 2014-02-11T07:18:20.541Z cpu8:425351)ScsiDeviceIO: 2331: Cmd(0x4124425bc700) 0x2a, CmdSN 0xd5 from world 602789 to dev "naa.514f0c5c11a00025" failed H:0x0 D:0x2 P:0x0 Valid sense data: 0x4 0x44 0x0 It much like language of another planet when I first time saw itJ. Let’s see how to “translate” it to human language. First, I split it to several sections: a) 2014-02-11T07:18:20.541Z cpu8:425351) b) ScsiDeviceIO: 2331: Cmd(0x4124425bc700) 0x2a, CmdSN 0xd5 c) from world 602789 d) to dev "naa.514f0c5c11a00025" e) failed H:0x0 D:0x2 P:0x0 Valid sense data: 0x4 0x44 0x0 Section A shows the UTC time when the error occurred. Section B shows what command is sent. (Actually I don’t even know what the command means is, please let me know if you know it.) Section C shows which world the command related

Hi there, I built a new personal website, hence I'll stop update here. Please go my  Wu's Blog  to get latest articles.

I didn't know ICANN request email address verification, I thought freedom everywhere outside China, but looks like it's not. :-) My domain was suspended due to that ICANN policy, and my QQ mailbox unable to recieve verification email from ICANN, what a unfreedom country it is! Finally I have to change my domain register mailbox to Gmail to get the email. Shit GFW! ( Check out here to learn more about GFW )

If you have set of group VMs and particular group can access each set VMs, you should grant access on vSphere Client or vSphere Web Client. SSO is slowly sometimes, you could use following CLI to do it more efficient. New-VIPermission -Entity " Folder Name " -Principal " Domaingroup name " -Role " Role name " You could do it faster for regular folder name or group name by excel and notepad: New-VIPermission -Entity " Folder Name " -Principal " Domaingroup name " -Role " Role name " Guess how to do it.

Your vHBAs or other PCI devices may stop running in ESXi 5.x when using Interrupt Remapping feature. This issue only impact to UCS blade BIOS version 1.4(3c), it has been fixed on 1.4(3j). Please refer to http://kb.vmware.com/kb/1030265 to see how to disable Interrupt Remapping feature in ESXi 5.x Also refer to https://tools.cisco.com/bugsearch/bug/CSCty96722 .

Serials console is very helpful to troubleshooting Linux problem, you can see additional system message via serial console if your Linux server hung. It is essential component on physical server for troubleshooting. It’s challenge to manage serial consoles if your datacenter is very big. You may deploy console server for central management of serial consoles, you don’t have to connect your computer with serial console one by one, you just need connect console server IP follow with port name by telnet protocol. Time comes to today, virtualization world. How you connect serial console of Linux virtual machine? Can we do exactly same like physical server? Answer is YES! There is couple of way to connect serial console of VM, each way has different benefit. I’m going to introduce the best one! VMware has a KB article 1022303 introduces how to implement virtual console server, but it’s not very clearly, I went to wrong way by follow up the KB. Deploy Avocent ACS v6000 virtual advanced c