A virtual network adapter is a program (instead of a physical network adapter) that allows a computer to connect to a network. A virtual network adapter can also be used to connect all the computers on a local area network (LAN) to a larger network such as the Internet or a collection of LANs.

Here, I would like to share how to change virtual machine virtual network adapter manually. In fact, you may know you can add a new virtual adapter and choose the adapter type from drop down menu.

Here you go:

1. Login to VMware ESX server
2. Type vmware-cmd -l and look for virtual machine (vmx = vm config file) which require change virtual network adapter
3. You may check VMware KB Article: 1001805 for available network adapters details.

# VMXNET — The VMXNET virtual network adapter has no physical counterpart. VMXNET is optimized for performance in a virtual machine. Because operating system vendors do not provide built-in drivers for this card, you must install VMware Tools to have a driver for the VMXNET network adapter available.

# Flexible — The Flexible network adapter identifies itself as a Vlance adapter when a virtual machine boots, but initializes itself and functions as either a Vlance or a VMXNET adapter, depending on which driver initializes it. With VMware Tools installed, the VMXNET driver changes the Vlance adapter to the higher performance VMXNET adapter.

# E1000 — An emulated version of the Intel 82545EM Gigabit Ethernet NIC, with drivers available in most newer guest operating systems, including Windows XP and later and Linux versions 2.4.19 and later.

# VMXNET 2 (Enhanced) — The VMXNET 2 adapter is based on the VMXNET adapter but provides some high-performance features commonly used on modern networks, such as jumbo frames and hardware offloads. This virtual network adapter is available only for some guest operating systems on ESX/ESXi 3.5 and later.

4. Edit Virtual Machine vmx file and choose virtual network adapter as show below:

Flexible
Nothing have to add into vmx file.

VMXNET 3
ethernetX.virtualDev = “vmxnet3″

Note: ethernetX = number of ethernet card.

5. Save the VMX file and power on your virtual machine.
6. Power on your virtual machine using virtual center or type # vmware-cmd your_virtualmachine.vmx start

Enjoy!

I would like to share how to configure memory “hot add” for Windows 2003 virtual machine.

Please make sure the virtual machine is power off before proceed and this is one time setup.

• Right click on virtual machine
• Click Edit Settings
• Click Options
• Select “Enable memory hot add for this virtual machine” under Memory/CPU Hotplug.
• Click OK

Testing time! Power on your virtual machine and increase your memory size on the fly now.

Note: You can increase the memory on the fly but NOT decrease the memory during virtual machine is power on.

Enjoy!

Many enterprise who have implemented virtual environments as a way to consolidate servers and centralize management are running may facing I/O bottleneck issue. No matter how many servers, switches, SAN storage or operating systems that you have, you’re still require to go through IO device.

Imaging you are running on multiple VMware ESX hosts that have more than 10 nics and multiple HBA cards each. How do you going to manage your cabling? How many network switches or port require? What is the costs? What is the maximum I/O you can get? Now Xsigo can help you on virtualization I/O.

What is Virtualization I/O? As I/O today is specify on storage and network throughputs. In most cases, we used to manage with seperate environment for Storage connectivities and Network connectivities. Therefore, we will have HBA FC connection as well as NIC connection for every servers we have in the Data Center. You will also have different manage switch exist in your DC which require more administrator to manage seperately. In Virtualization, we speak about consolidate, increase utilization, centralized manage and etc. Xsigo Virtualization I/O will able to achieve the concept for us to standardize, consolidate, simplify, increase throughput and utlization for the environment we invested in DC.

Let’s imagine what happen today, you will have 4Gbps connection on FC from your server to the storage, but you will not necessary utulize that. You will not able to allocate the under utilize bandwidth to the rest of the client or connection which require, which is consider a waste. It happen the same thing to Network connection, in most cases, you may not require 1Gbps connection for each servers. Without Virtualization I/O, we will end up buying more manage switches, invest more bandwidth in Data Center and under utilize it. This technology even provide a better bandwidth for each connection and allow the combination for both storage and network. This will simplify the cable managment and adminstration time lead for long term solution. Host Channel Adaptor is cheaper if we compare the price of Host Bus Adaptor today. Is Virtualize I/O make sense? My personal answer is yes and it will just do exactly the same as what VMware provide, fully utilize your environment, for cosolidate, simplify and central manage for I/O in data center.

Here’s an alternative solution for you: a Bash script to run on your ESX Server.

Sample screen shot:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
VMWARE ESX Management Tool Script
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Author : http://malaysiavm.com/blog
Version : 1.00.20081107.14.31
Supported ESX Version : 2.5 – 3.5
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

0. VM Informations
1. Register VM
2. Unregister VM
3. Check VM Status
4. Power ON VM
5. Power OFF VM
6. Suspend VM
E. Exit

Choice:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Known Issue:
1) DO NOT support VM with space in the middle, ex: “MY VM Server”. It will show as 3 blank VM servers, and none of these 3 are working.

Note:
1) This script need to execute as ROOT on your ESX Server (DO NOT Support 3.0i and 3.5i).

2) There is absolutely no guarantee from us and use at your own risk!

DOWNLOAD HERE
Please feel free to modify, share and comment to make it perfect.

This work is licensed under a Creative Commons License permitting non-commercial sharing with attribution.

Basically setting up a brand new Windows 2003 machine is pretty simple but setup a new Virtual Machine took me 2 days. The most important is my VM template is go missing. The quick solution is search for VM template and register (add to inventory) again.

SSH into my ESX server using putty and search for VM template file with extension “.vmtx”.

[root@malaysiavmesx01 vmfs]# find /vmfs -name *.vmtx
/vmfs/volumes/465eeddb-89b75750-a52d-011aa0289d15/W2K3STD/W2K3STD.vmtx
/vmfs/volumes/465eeda7-2a63d436-724b-011aa0289d15/RHEL5/RHEL5.vmtx

How to register a VM template using CLI:
[root@malaysiavmesx01 vmfs]# /usr/bin/vmware-cmd -s register

In my case, I will register my VM template as example below:
[root@malaysiavmesx01 vmfs]# /usr/bin/vmware-cmd -s register /vmfs/volumes/465eeddb-89b75750-a52d-011aa0289d15/W2K3STD/W2K3STD.vmtx
[root@malaysiavmesx01 vmfs]# /usr/bin/vmware-cmd -s register /vmfs/volumes/465eeda7-2a63d436-724b-011aa0289d15/RHEL5/RHEL5.vmtx

Probably you can check previous article “How to re-register a VM once it had been removed from ESX” posted by Craig for register a VM template using Virtual Center and browse through the data store.

The lesson tell me I MUST backup SQL database and VM template keep in the database.

• Login to Virtual Center
• Right click on your Cluster
• Click Edit Settings
• Click VMware HA
• Click ‘Enable virtual machine monitoring‘

If you don’t see any ‘VMware HA’ column available, please make sure you have VMware HA enable.

• Login to Virtual Center
• Right click on your Cluster
• Click Edit Settings
• Click General
• Click Features
• Click Enable VMware HA

Hope this is useful.

Each of the patches had it’s own KB to describe the patches details. I am currently patch up my test machine by using the Update Manager in my Virtual Center. If you plan to do the same, please ensure you update manager had the latest inventory updated from the Internet.

ESX Patches Download

I am strongly disagreed with these comments as most of us know that the reason of consolidate and virtualization, is not for performance reduce, is really to improve efficiency and utilization of the hardware that we purchased. Networking play a big parts in VM infrastructure and most of the time, it did become the performance bottle neck for most users. Let me talk about some example below.

1 of the case i saw here, which the engineer configure it’s ESX in to a server which only have 2 physical NIC connected for VMnetwork interface to allow VM to be connected to the production network. There is more than 10 VMs on the ESX servers which connected to the 2 gigabits NIC and share among each others. In physical environment, for 10 physical servers, they always get 1gb per servers and is not in shared condition. But now, since virtualized, they need to share 2gb with 10 VM. Guess what, the users start complaining slow performance on the network file transfer, the backup through Network is slow as well as any reason that the network slowing down due to the high peak bandwidth utilization from any of the VM which shared on the 2 NICs. Not only the NIC causing the performance issues, and the switches uplink to the DC switches had also another thing you may need to keep an eye on. No matter how many gigabits connection you connected your servers through, it will still depend of the total uplink for your switches to route the traffic to the DC.

In this case, they not really figure out the performance issues as they won’t notice this performance bottleneck in the performance chart from Virtual Center. Most of the time, only the network guys will able to identified these issues. It really hit hard to some of the engineer which push hard on the virtualization, but it did become performance sacrification to the customers at the end. I will not want this to happen for myself, as we had invested SAN storage & High capacity servers which is not cheap solution.

Therefore, I will recommend that to deploy the VM Infrastructure in to enterprise environment in Data Center, we should always plan ahead including the Networking conditions. Again, Virtualization not meant performance sacrification, and virtualization do provide a lot of benefits which physical servers don’t.