Virtualization Team

Till today everywhere I looked recommended using RDM over VMFS for performance (when a higher I/O is required), though today while studying for my VMware Design Exam I have got my hand on the “ Performance Characterization of VMFS and RDM Using a SAN” document by VMware. The interesting executive summary of the document is copied up to the letter below:

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Executive Summary:

The main conclusions that can be drawn from the tests described in this study are:

• For random reads and writes, VMFS and RDM yield a similar number of I/O operations per second.

While preparing for my VMware Design Exam, I have stumbled upon this great pdf that document VMware ESX & ESXi connections & ports in details. It even cover the connections & ports for VMware additional components like VMware Update Manager & vCenter Converter.  Although many documents do the same, what got my attention is all this are fitted into one detailed compact image. I though this document will be useful for many others planning to take the exam, or even Virtualization Experts who just want to design their network & adopt for the ports they need to open through firewall. Below is a small foot print of the image. To download the document just hit on the image below.

VMware ESX host can disconnect from VirtualCenter & have a problem connecting to it again for many reasons. Below I will cover few ways to diagnose the problem, few common resolutions to this issue.

In these cases usually the first thing you want to do is to log on through ssh, vcli, or directly on the server console & check the following log files for errors:

Vmkernel – /var/log/vmkernel
Vmkernel Warnings – /var/log/vmkwarning
ESX Server host agent log – /var/log/vmware/hostd.log
Service Console – /var/log/messages
VirtualCenter agent – /var/log/vmware/vpx

Note: it would be great if you get to know what each of the above log files is for.  VMwareWolf has a great post explaining these log files that can be found at: http://www.vmwarewolf.com/which-esx-log-file/

As many VMware ESX monitoring tools are hitting the market place, and with the tend of these tools being dependent on SNMP (example: Starwind Free VM Monitor for VMware ESX), the more I am getting the question on how can I enable SNMP on my VMware ESX Server.. The instruction below will cover how to enable SNMP on VMware ESX (Note: VMware ESXi 3.5 does not support SNMP queries.).

To enable SNMP on VMware ESX Server 3.5:

1. Login to the console as root
2. Open snmpd.conf file with your favorite editor (Usually you can find snmpd.conf  in /etc/snmpd) and add “rocommunity xxxx” where xxxx is your read-only community string).

SolarWind has released a new VMware ESX Monitoring tool called VM Monitor. The new tool can monitor the status & utilizaiton of your ESX Servers as well your Virtual Machines. SolareWind VM Monitor uses the SNMP Service on VMware ESX to monitor your enviornment. As VMware ESXi does not support SNMP queries,  it’s still not supported by SolarWind VM Monitor. In order for SolarWind to work with your VMware ESX you will have to enable SNMP on your ESX hosts. A good instruction on enabling SNMP on VMware ESX Host can be found at: VMware ESX How to enable SNMP.

Below you will find a good video of the SolarWind VM Monitor in action, please note the video cover a bit of SolarWind Orion product which is not a free product.

If you don’t know what is VMware EVC or you need to find out more about it, please look at my last post VMware EVC enhanced VMotion Compatibility enable VMware VMotion across CPU generations

Ok, if you had read that and now wondering how to get it setup without having to shutdown your virtual machines. Then this small tip is for you.

As you know & I had mentioned that in my previous post on this topic that VMware will request you to shutdown all the virtual machines you have running on the cluster you want to enable VMware EVC for. To avoid having to shutdown your virtual machines what you can do is to create a temp cluster with few temp servers on it & VMotion your VMs to these servers. Enable VMWare EVC on your evacuated production cluster. Then again VMotion the Virtual Machines back to your original production cluster.

Everyone who had been using VMware for a while, would appreciate VMware VMotion. Actually VMware VMotion have always been a distinguished feature of VMware ESX servers. Despite of VMotion has always been a great feature, people using it at earlier stages used to have a tough time when having to use it across different CPU generation. That meant companies had to actually put similar hardware server in the same cluster, to guarantee that VMotion work smoothly. This was not possible at all the time, and was a tough call for implementers as they had to cheat masking manually in order to avoid VMotion not accepting to run between different CPU genrations.

It seems to me many people are facing the same ugly error when they try to convert a physical server to a virtual server using VMware Consolidation Planning tool. The error usually get after the tool has finished annalyzing the physical machine & it was deemed ‘Ready for consolidation’ with Confidence ‘high’.

When the user select ‘Plan Consolidation’, select the server, and click on ‘Consolidate’, they get the famous error message, “A general system error occurred: Ufad server is not running.”

The image below show the error:

As a lot of people seems to stumble by this every day, I have decided to discuss the way I usually resolve this problem.

I have just came across a video of Microsoft trying to bust VMware top Myths, but what is funny to me it seems Microsoft had just busted them selfes in the video than anything else. The link to the video is below:

http://www.microsoft.com/video/en/us/details/f8c3314f-c82d-4f8d-8b19-6a59733670f8

I have seen Gabe reply on his blog at his Gabes virtualization Blog which seems to be a great busting to this video. Below is what Gabe is saying on his blog or please read it directly on Gabe blog at http://www.gabesvirtualworld.com/?p=445. Please give credit to Gabes & read this on his blog .

============== Directly from Gabes Virtualization Blog ===========

A good amount of ESX admins ask on dialy basis how to change the VMware ESX Service Console Vlan using command line. As I decided to save time by writing the steps for these kind of questions to send it to others when asked. I will document these commands in here:

First of all check which vSwitch the Service Console is on (and the name of the Service Console) with esxcfg-vswitch -l (Note: The default service Console switch is vSwitch0 & default name is “Service Console”.)

To set a vlan id on the service console use:

esxcfg-vswitch vSwitch0 -v X -p “Service Console” (Replace X with the desired VLAN number)

When ever I attend a VMware presentation, one of the most common question “How would we handle our USB or parralel licenses dongles in VMware ESX.” Are they supported? Can I get them to work some how? What make the question more critical that most presenters are from a sale or pre-sale background and does not have the clear answer. The real answer to the question, yes its workable but you might need some third party utility to get the required setup to run. Some good resources to get you started are below:

VMware ESX Server Using AnywhereUSB to Connect USB Devices

VMware esx21admin_modvm_parallel_running

USB Device Support within VMware ESX 3.x and ESXi

It might be the time for you to upgrade your VMware ESX servers to VMware 3.5U3 and Virtual Center 3.5U4.

You might even just want to upgrade to any version of VMware ESX & vCenter 3.5. Then this guide linked to below is all you need. It has a great step by step instruction of the process & better its provided by the solution Vendor VMWare .

VMware ESX & Virtual Center Upgrade guide

You might wake up for a bad day after a power outage or a storage failure. You thought it was over, after you had succeeded to bring all your machines back up and running. In few minutes you found out that some of your virtual machines are missing. After a small investigation you found out that your VMware Datastores (VMFS) are empty when you try to browse them from VMware vCenter or VI client. If you face this problem there is a big chance that your VMFS Partition table for these LUNs or disks are missing.

To Check Your VMware ESX server VMFS Partition table follow the following procedure:

Finally back home . Don’t get me wrong Cannes was great, though nothing like being back home.

OK for people who did not get to join us in Cannes, I had for them a free ticket for the replay .

I wish I could afford to give our visitors a VMworld pass for free, but I have not been making that much money yet. Here I will make up for the tickets, by sharing with you the links for the top 10 VMware VMworld 2009 Vids including the CEO Keynotes & the closing . So you will feel like you were there with us. Below are the long waited links .

VMware VMworld 2009 General Keynotes Videos

VMworld Europe 2009. VMware has used the VMworld Europe 2009 to announce two new products that will be available this year:

1- vCenter Server Heartbeat:

Comes to solve the problem arising from a possible collapse of the server that manages the VMware virtualized platforum, specifically vCenter Server earlier known by Virtual Center. The vCenter Server Heartbeat comes to provide High availability for the vCenter. Prior to vCenter Server Heartbeat you were only able to have one vCenter to manage your infrastructure if that vCenter fail VMware’s Live migration with VMotion, load balancing with Distributed Resource Scheduler (DRS), license management, and performance monitoring all cease to function.