VM /ETC

Posts Tagged ‘virtualmachine’

If you thought that because all ESX virtual machines (VM) share a virtual portgroup on a virtual switch (vSwitch) inside an ESX host you could easily sniff all VM traffic with a protocol analyzer like ethereal or wireshark, when you tried it you found out you were wrong. If I am not mistaken, ESX vSwitches are considered layer 2 devices and come with all the expected security and isolation. However, you can make some relatively simple vSwitch design and setting changes to turn a VM into a virtual sniffer and monitor all other VMs on that same host. Another option is a free virtual appliance that can allow you to use your physical monitoring tools to watch your VMs. This post explores both of these free VM sniffer alternatives.

I’m going out on a limb here reporting what I’ve learned about VM sniffers, but I figure that passing on what I know so far would be helpful to VM /ETC readers. At the very least, use the info in this post to get you pointed in the right direction. Fill me in on what I’ve missed, please! Read the rest of this entry »

One of the advantages of running virtual machines (VMs) on shared storage is that if you need to rebuild your ESX host(s) you won’t lose your VMFS volumes or the VMs. But, what if you can’t VMotion evacuate the VMs to another host with extra capacity first? This scenario means the VMs will no longer be registered on an ESX host once you are finished. Importing VMs with the datastore browser is simple enough, but what if you have hundreds of VMs to import? Manually importing that many VMs will take hours.

Luckily, the built-in ESX console command vmware-cmd with the -s option allows you to mass import VMs via some simple scripting. Ed Haletky pointed this out to me via Twitter, and then Duncan Epping tweeted me a post of  his that contained the following batch script he used for mass VM imports in slightly different scenario :

for i in `find /vmfs/volumes/ -name "*.vmx" `
do
echo "Registering VM $i"
vmware-cmd -s register $i
done

To use the above code save it as a text file with a .sh extension. For example “importvms.sh”. Place the file on anywhere on your ESX host and then as root run

#./importvms.sh

updated 3.12.09 – My Softchoice colleague, Michael Cocat out of our Chicago office, modified the original script above to work when spaces exist in the VM (and .vmx) name. Michael also likes to run the script as a single line entry on the ESX Console. Here’s the updated command in single line format:

find /vmfs/volumes -name “*.vmx” | while read LINE; do echo “registering VM $LINE”; vmware-cmd -s register $LINE

updated 3.12.09 – I also want to point out that this script will not place the VMs back in Resource Pools or Folders. The VMs are imported into the root of the object tree because the resource pool and folder information is not stored in the .vmx file. Once you have the VMs back registered with the ESX server you can simply drag and drop them into resource pools and folders again. Thanks to Jason Boche for bringing this up, and pointing out it is not really a fully automated recovery process. It is still a much better alternative to manually importing each VM with the datastore browser which will prompt you for Resource Pool and VM folder placement.

To find out more about the vmware-cmd options and switches check out

http://www.vmware.com/support/esx21/doc/vmware-cmd.html

and

http://www.esxguide.com/esx/content/view/2/25/

Did you take the time to plan for VMware Update Manager (VUM) when designing your virtual infrastructure architecture? Planning focus is usually on VirtualCenter (VC) server’s requirements, but then, in my experience, Update Manager and it’s default local SQL 2005 Express database seem to be added on the VC server simply because the installer is prompted about VUM during the VC setup routine. This scenario can create a poor performing VUM implementation.

Recently on the VMware Performance Team’s VROOM blog, John Liang’s post titled VMware Update Manager Performance and Best Practices Paper Posted announced a new whitepaper that should be a must read for any virtual infrastructure administrator preparing to use (or already using) VUM. The .pdf is a 14 page discussion on the topics that impact VUM such as performance, networking, resource consumption, and even virus scanning.

I find a few of these recommendations interesting, and the whitepaper leaves me wondering how common using VUM for virtual machine OS patching really is. I’ve created two informal polls, so please take a second to complete them and maybe we can get a quick gauge on how VUM is commonly implemented.

[poll id="2"][poll id="3"]

The whitepaper is a quick, informative read that I strongly encourage, but the following list of best practices was copied from the whitepaper’s Conclusion section.
Read the rest of this entry »

It happens more frequently than I would ever imagine, but from time to time I find clients have not installed the VMware tools in their virtual machine’s (VM) operating system. I find it more often in Linux VMs than Windows, but I’ve discovered it for both types of guests none-the-less. Some times the tools install is overlooked or forgotten, but every once in a while I am told something like “Does Linux needed VMware tools?” or “what do the VMware tools do for me anyways?”.

Well, I do not have any unique insight or clever commentary to add, but I am providing the following cut and pastes from the VMware .pdf Basic System Administration Guide as a easy reference. At the very least this post will save me some time because I won’t have to dig this info out of the .pdf again when I am asked.

The following sections provide info on what you install when you install VMware tools as well as steps for installing the tools for both Windows and Linux VMs. The rest of this post is not my material but comes straight from the linked guide above – although not necessarily in the order it appears in the original document, however. Download and read the current version for yourself! Read the rest of this entry »

The much anticipated announcement of a change in Microsoft licensing policy for virtual environments was delivered today as promised but with an unexpected let down. Microsoft has waived the 90 day mobility restrictions for applications like Exchange, SQL, Sharepoint, Systems Center Operations Manager, and many others but still limits the Windows Server operating system. Microsoft, apparently only concerned with silo-ed hypervisor deployments like Hyper-V, continues to only allow the migration of a virtual machine operating system once every 90 days. Microsoft considers a VMotion or live migration of an entire virtual machine as a transfer of license between hardware platforms.

The following paragraph was taken from the Overview section of the new Application Licensing Mobility Brief: Read the rest of this entry »

I posted a while back about VKernel’s Alex Bakman and his whitepaper on preventing performance bottlenecks on your ESX hosts. This time I am posting about another topic inspired by Alex dealing with how to chargeback for virtualization. More and more companies are beginning to talk about chargeback in virtual data centers, but many struggle with coming up with a formula for actually implementing such a model. VKernel has a great solution for this and provides for download both a free Excel calculator and a complete virtual appliance. I provide a little more information on both of these Vkernel solutions in the rest of this post.
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It’s good to see more and more of the various Linux distributions prepackage enhancements that benefit the operating system when running in virtual machines. This also makes life a whole lot easier for the administrator configuring the virtualized OS. Building VMs is already fast in comparison to physical servers, but having to take the time to modify config files to get a usable screen resolution can get on your nerves real quick! Anyone who has ever built a Linux VM over the past several years has most likely experienced Xorg (screen resolution) problems and knows what I am talking about.

Today, thanks to VMware making a large part of the Linux version of the VMware Tools open source, the latest distribution of Ubuntu (8.04 or Hardy Heron) includes the xserver-xorg-video-vmware package in it’s core installation. Hopefully the other popular distributions are doing the same. Frankly, I haven’t had the chance to explore CentOS, Fedora or Red Hat, but recent announcements seem to indicate that the same virtulized enhancements are taking place for those distros too.

So, what this means is that you Read the rest of this entry »