Archive for June, 2009

Reduce numbers of Server Racks in Data Center

Posted on June 13th, 2009 in Data Center, Hardware, Industry News, Virtualization, vSphere | No Comments »

With my last 3 years of experience, I had seen numbers of companies require significant expansion in the data center to support the business growth, just because of the additional 200 to 2000 servers or storage shelves they need to put in to the data center. With the technology today, it does help us to reduce the space we need to slot in the servers, and storage thanks to the success of virtualization and higher capacity disk drives in the market. To run a full solution of data center with less number of server racks for SME and enterprise, will no longer be a dream due to some facts below,

  1. Higher consolidation ratio in virtualization with the latest CPU, memory and servers performance
  2. Higher capacity disk drive which significant reduce the number of storage expansion require
  3. Virtual I/O which allow the higher utilization of the available bandwidth in data center
  4. UCS to provide consolidation and higher capacity of bandwidth to support network and storage utilization in the data center

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How To Enable Root Password for Single User Mode on vSphere 4

Posted on June 11th, 2009 in Tips, vSphere | No Comments »

You can easily found “how to reset the root password on ESX” articles on the web for an example VMware KB article 1317898, xtravirt, or Petri.

However, unauthorized entry into single user mode is a risk. For security enhancement, you should enable password protect GRUB and enable root password for single user mode on vSphere 4.

How To Enable Root Password for Single User Mode on vSphere 4

  • Login to vSphere server as root
  • Edit /etc/inittab file
  • # vi /etc/inittab
  • Insert “~~:S:wait:/sbin/sulogin” and reboot
  • inittab

    What is this mean?
    man inittab shows
    id:runlevels:action:process
    id = is a unique sequence of 1-4 characters which identifies an entry in inittab
    runlevels = lists the runlevels for which the specified action should be taken
    action = describes which action should be taken.
    process = specifies the process to be executed.
    S = Single user mode
    wait = The process will be started once when the specified runlevel is entered and init will wait for its termination.

  • You should be able to see password prompt during single user mode boot up
  • Enable Root Password for a Single Mode

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VMotion compatible from ESX 3.5 to vSphere 4

Posted on June 4th, 2009 in Tips, vCenter, Virtualization, vSphere | 1 Comment »

I am currently doing some test to simulate the real update requirement for my production VMware Farm to be upgraded from ESX 3.5 to vSphere 4. To minimize the impact to our production system, we may want to do this with as minimal impact as possible. Due to the virtual hardware version and tools upgrade require, is pretty tough for us to perform the entire upgrade at 1 time. Therefore, our plan is get the host upgraded and follow by each individual virtual machine to be upgraded follow the suitable timing for different business unit. HA and DRS will need to be disable temp during the ESX upgrade.

I am able to get the ESX 3.5 to be manage by the latest vcenter. A vmotion from ESX 3.5 to vsphere 4 had been successes too, but the latest version of virtual machine which built from vSphere 4 might not compatible to vmotion back to the ESX 3.5 hosts. At the same time, if you have different processors chipset in the environment and require EVC to be turned on, it may be a little challenge to do so. You may want to ensure the EVC to be done with no down time.  You may need to refer to my previous post about how to enable EVC with no down time.

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