ESXi Chronicles

One of the beauties of a thin hypervisor architecture like VMware ESXi is the fact that the entire state of the system can be described in a much more compact fashion than is possible with a general-purpose operating system.  This include areas such as: virtual networking configuration, storage settings, and host infrastructure services such as NTP and logging.  All changes to the system occur through well-defined APIs, so it's easy to know what can be modified.

This fact, among other things, makes it easy to back up the entire state of an ESXi host, in case you later need to restore the system to the same state.  The vCLI (vSphere Command Line Interface) has a command specially built for this purpose: vicfg-cfgbackup.  A recent blog posting on vmwaretips.com goes over a real-life situation where this command proved invaluable.:

What is the fastest and easiest way to turn an existing server or higher-end desktop into your new virtualization consolidation platform? VMware Go. It will guide you through finding a suitable server on your network, installing VMware ESXi, configuring ESXi, and migrating or installing new virtual machines. Best of all, it's free. This article shows you step by step how to use it.

In an earlier post, we explained how ESXi is just as fully-featured as classic ESX, and what it can do just depends upon what features are licensed in a given deployment.  Some people are surprised that this much functionality can be provided in such a small package.  Our colleague Eric Gray has posted a two-part series on his vCritical blog that goes into great detail about this.  The first part dissects an ESXi image and shows how, even though an ESXi deployment requires about 1 GB of disk or flash memory space, the actual ESXi image is only around 70 MB (the rest being used for other purposes).  The second part shows how to get a full-blown ESXi system up and running on a mere 64MB USB stick.

Of course, we don't recommend squeezing ESXi into a smaller space than what we preconfigure, since that extra content (such as vSphere Client and VMware Tools) is all useful stuff.  But if you want to satisfy your curiosity, then check out those blog posts.

VMworld is only two weeks away, and we wanted to give you a run-down of the ESXi sessions that will be at the show:

-- The ESXi Team: Amir, Jaleh, Charu

As more of our customers start migrating from VMware ESX to ESXi, we would like to start showcasing some of their deployment experiences on this blog. We recently published a case study on the ESXi deployment of Kroll Ontrack, the world leader in providing legal technologies and data recovery products and services.

Kroll has been a long time user of VMware ESX, but for their latest virtualization project, they decided to deploy an embedded version of VMware ESXi due to its more reliable architecture and simpler management requirements such as less patching and faster provisioning.

“We chose ESXi to virtualize our file servers based on lessened patching requirements and the ability to get away from using hard drives in the servers,” says Joel Fuller, a technical architect at Kroll. “ESXi is very easy to configure and deploy. You basically take a USB key and push out a scripted configuration to it, and it’s done.”

With a goal of migrating 500 existing physical file servers, Kroll adhered to a schedule of converting approximately 15 file servers per week, with an additional 25 servers converted during monthly maintenance windows. Each file server is built from a template, making it quick and easy to provision new virtual machines. Kroll prepared PowerShell scripts to automate the rollout.

Kroll currently has 145 ESXi hosts, allowing them to consolidate 20 racks down to only 3. They are very satisfied with their ESXi rollout: “VMware ESXi lets us get more life out of our infrastructure while giving us a simpler and more secure operational model,” says Fuller. “That makes us a much more scalable organization.”

Read the full case study. If you have deployed ESXi, please let us know. We would love to feature you on our blog.

The ESX team

After people have learned about ESXi, and understand all the benefits (less patching, easy deployment and manageability, etc), one of the first concerns that they raise is around hardware management. Many IT shops use management tools from OEMs such as Dell OpenManage Server Administrator (OMSA) to do things like hardware health monitoring, asset inventory, and viewing alert and command logs. Traditionally, this functionality has been provided for ESX by an agent running in the Service Console. Without the Service Console, they ask, how could this be done for ESXi?

Ever since ESXi was released almost one and half years ago (as version ESXi 3.5), VMware and Dell have been working closely together to provide hardware management capabilities via an agentless model, using industry standard interfaces for management such as WS-MAN. With the release of ESXi 4, the management capabilities of Dell servers running ESXi is almost at parity with ESX 4.   In particular, the following features are available to OMSA from an ESXi host

• View server and storage asset data  
• View server and storage health information
• View alert and command logs 
• Configure hardware (storage, BIOS, etc.)

All this is available via the familiar web-based interfaced used for servers running ESX.  Here is a screenshot of the Power Tracking Statistics Page:

In addition, we have enhanced VMware vCenter (formerly VirtualCenter) Server to provide fairly extensive hardware-level monitoring as well. With vSphere 4, this capability is fully integrated with the rest of vCenter, e.g. you can set alarms on hardware faults. (Note that monitoring functionality is available even for the stand-alone, free version of ESXi 4; simply look in the vSphere Client).  Here is a screenshot of a Dell System being monitor in vCenter:

To learn more about the management capabilities of ESXi 4 running on Dell PowerEdge servers, see this new joint white paper from VMware and Dell. There is also an online article in the June 2009 edition of Dell Power Solutions that talks about this.

Recently, IBM announced a new Cloud Computing offering called CloudBurst.  From the product page:

IBM CloudBurst is a complete IBM Service Management package of hardware, software and services, which simplifies your cloud computing acquisition and deployment.

This blog entry from the ibm.com Community describes the software used to provide the resource abstraction layer:

Cloud Software Configuration:
•IBM CloudBurst service management pack
•IBM Tivoli Provisioning Manager v7.1
•IBM Tivoli Monitoring v6.2.1
•IBM Systems Director 6.1.1 with Active Energy Manager; IBM ToolsCenter 1.0; IBM DS Storage Manager for DS4000 v10.36; LSI SMI-S provider for DS3400
•VMware VirtualCenter 2.5 U4; VMware ESXi 3.5 U4 hypervisor

What's interesting to note is that the solution is based on the prior release of ESXi, version 3.5  With all the enhancements that have been added in ESXi 4 (which we'll talk about in upcoming blog postings), there should be no doubt that ESXi is the ideal architecture for building clouds of any size -- as many of our customers are already doing today.

The ESX Team

Similarly to ESX 4.0, ESXi 4.0 is a 64-bit hypervisor. This means that the underlying hardware needs to support 64-bit operations in order for ESXi 4.0 to work. As you know, 64-bit instruction sets allow access to more system resources, such as memory and storage, as compared to their 32-bit counterparts.

While ESXi 4.0 does not work on older, 32-bit servers, it has a much larger hardware compatibility list than ESXi 3.5. You can look for ESXi 4.0 compatible systems here.

As of writing this blog, over 60 vendors have participated to deliver

• 137 servers qualified and certified for ESXi 4.0 (embedded)
• 663 servers qualified and certified for ESXi 4.0 (installable)

Comparatively, there are 795 servers on ESX 4.0's hardware compatibility list.

All mainstream, high-volume servers are in the ESXi 4.0 hardware compatibility list (both for embedded and installable form factors). Here is partial list of current server vendors that certified systems for ESXi 4.0:

• AMAX Information Technologies
• Cisco
• Compusys
• DELL
• Fujitsu Siemens Computers
• HP
• IBM
• Intel
• Lenovo
• Rackable Systems
• Samsung
• Sun Microsystems, Inc.
• Unisys
• Verari
• Wipro

A final note: When installing ESXi 4.0 on a 64-bit server, please ensure that the BIOS settings allow that server to run in the 64-bit mode. Many servers are 64-bit capable but are set to operate in a 32-bit mode.

The ESX Team

[You may have come here via search. Welcome! If you have specific questions on ESXi, please visit the ESXi Community. There are many experts there that can answer your questions. Thanks!]

VMware made the decision to make VMware ESXi, our next generation hypervisor, freely available to proliferate the VMware platform and allow administrators to prove its value at no cost. However, the fact that the older platform, VMware ESX, is not also available for free has lead some people to believe that ESXi may be inferior or not as feature-rich as ESX. This is certainly not the case. In fact, the opposite is true. ESXi has a superior architecture and we encourage customers to deploy ESXi as part of any new vSphere deployment. Our future posts will compare ESX 4 and ESXi 4 in detail on topics like hardware compatibility list, performance, and management to demonstrate that ESXi is either on par with or superior than ESX. But for now, here are some key points you should know about ESXi vs. ESX:

1. The functionality and performance of VMware ESX and ESXi are the same; the difference between the two hypervisors resides in their packaging architecture and operational management. VMware ESXi is the latest hypervisor architecture from VMware. It has an ultra thin footprint with no reliance on a general-purpose OS, setting a new bar for security and reliability (learn more).
2. In the future, ESXi’s superior architecture will be the exclusive focus of VMware's development efforts.
3. New and existing customers are highly encouraged to deploy ESXi. Many Fortune 100 companies have already standardized on the ESXi platform.

Although one instance of free VMware ESXi can be managed with the vSphere Client, the free version has two important limitations:

1. vCenter cannot manage free ESXi without a vSphere license as its APIs only grant read-only access.
2. Automated scripts cannot change hypervisor settings. 

However, once ESXi is licensed for any vSphere SKU, its APIs become both read- and write-accessible, unlocking the full functionality of vCLI, vMA, PERL Took Kit, Powershell Tool Kit, or other VMware management interfaces.The table below, available here, explains how different license levels unlock ESXi (and ESX) functionality. Please note that vSphere Essentials, an all inclusive package that can be deployed on up to three servers, is priced at under $1000. 

The ESX Team