ESXi Duplicate vmk0 MAC Addresses

For the ICM class there are 12 different lab environments with 2 virtual ESXi host each. To deploy these ESXi hosts I clone them from a master ESXi template that is preconfigured and has a local datastore with all the necessary class files and software. After I deploy each virtual machine I test connectivity and before last nights class everything seemed fine.

To locate MAC addresses on VMware ESXi servers using command line interface:

– Enable root login for SSH/SCP clients (click for my blog on how to enable RL)
– Login to VMware ESXi via SSH
– Run the command- vim-cmd hostsvc/net/info | grep “mac =”
Now you have your list of MAC addresses. Login to VMWare vSphere client and match the MAC addresses to the Network Adapters section.

Once the class started accessing the lab environments we started seeing some network issues. Connections to the lab ESXi hosts were being dropped every few seconds, restarting the management networks would bring back connectivity but only for a short time. The issue turned out to be that each of the 24 hosts had the same MAC address assigned to vmk0 – oops!

The vmk0 is a virtual interface and a MAC address is generated for it when it is created. When the ESXi template is cloned the vmknic and its configuration (Name, MAC, MTU, and IP settings) are also cloned. Accessing ESXi Shell and running esxcfg-vmknic -l will list the configured vmknics and the configurations (including the MAC) of each.

There are 2 ways to correct this in the cloned ESXi hosts. One way is to delete and recreate the vmk interface. The other is to set the vmknics to use the hardware MAC address of their physical uplink NIC. The process for both of these options can be found in this kb article.
For the lab environment I set the vmknic MAC to follow the hardware MAC.

esxcfg-advcfg -s 1 /Net/FollowHardwareMac

After setting this and rebooting the vmknic (vmk0) now uses the MAC address of its physical uplink nic by entering this: esxcli network ip interface set -e false -i vmk0; esxcli network ip interface set -e true -i vmk0 .

Sysprep: A fatal error occurred while trying to sysprep the machine


Setting HKEY_LOCAL_MACHINE\SYSTEM\Setup\Status\SysprepStatus to 7

Setting HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\SoftwareProtectionPlatform\SkipRearm to 1
Renaming (or deleting) C:\Windows\System32\sysprep\Panther

Memory test, check, analyze on linux

I know there are tones of information about how and what to use to analyze the memory usage on linux.

However I’m publishing some useful ones that can be helpful to start with:

Display amount of free and used memory

free -m

Display swap usage summary

swapon -s

Display user-process resource limits

ulimit -a

List processes sorted by memory usage

ps aux –sort -rss

mount: Cannot allocate memory

Trying to mount -a on a linux system with windows share was giving me the following error

mount: Cannot allocate memory

The problem seems to be on Windows system where share is located. Quick and temporary workaround is to restar Lanmanserver service and retry mount -a.

Permanent fix that should help is to edit a registry setting and restart the service as below:

reg add HKLM\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters /v Size /t REG_DWORD /d 3 /f
sc stop LanmanServer
sc start LanmanServer

Windows User Profile Deletion Utility

Useful tool from Microsoft to delete correctly old and unused profiles.


Disabling Navigation Pane in Explorer Windows 2008

From my self experiments I discovered below keys that control the Navigation Pane Per User in Open and Save As Dialog boxes on Windows server 2008 and Windows 7.


To Disable Navigation Pane:








To Enable Navigation Pane:

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FLV 404 Error On Windows 2003 Server IIS

I was working on a streaming video file for a client this morning using Flash and a linked FLV video file. Everything worked nicely – the Flash media player is so badass – until I uploaded it to the production server. Suddenly, the movie didn't play at all. Nothing I did seemed to work; cleaning the cache didn't do anything; all the paths were right. It wasn't until I tried to access the FLV file directly and got a 404 File Not Found error that I realized something was fishy.

After some Google searching, I came across this Adobe Tech Note that says that:

When Flash Player movie files that stream external FLV files (Flash videos) are placed on a Microsoft Windows 2003 server and then viewed in a browser, the SWF file plays correctly, but the FLV video does not stream. These files work correctly if tested on other operating systems. The issue affects all FLV files played via Windows 2003 server, including files made with the Flash Video Kit for Dreamweaver MX 2004.


The good news is that there is any easy solution:

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How to find Bluetooth & WLAN MAC address of Nokia mobile device


I needed the latter one to whitelist my N86 on my home wifi network so thought of keeping the codes as reference for future use.

At the standby screen (idle position), just type in the following codes :

Bluetooth MAC address

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Printscreen doesn’t work with Photoshop – Solution

Recently I've had a couple of incidents when pasting screenshots from printscreen into Photoshop didn't work — Alt Print Screen or Printscreen. Read more

The operation failed. The error is: This operation cannot be performed on the current domain

Keep getting the following error message while trying to configure trusted relationship between domains 

"The operation failed. The error is: This operation cannot be performed on the current domain" ?


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