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vSphere 4.0 Quick Start Guide review

Pronunciation: (un”poot-dou’nu-bul), [key]
—adj. Informal.

Adjective meaning consistently and irresistibly interesting. Typically refers to a book that is so well written and entertaining as to be difficult to (literally) put down and pause away from.

Normally a term used to describe novels, but the vSphere Quick Start Guide certainly fits the definition. Last month I was finishing three major projects and needed to write my VCDX application in one week, but somehow it kept ending up in my hands. So what’s so special about this book and how does it distinguish itself from the competition?

The book central theme is providing tips and ‘how to’s’ and it does this rather well. The book handles the traditional subjects, such like vCenter, Host, Virtual Machines, Networking and Storage. Besides the concise, easy to follow and non-ambiguous way the tips are written, I really like the minimal use of screenshots. This allowed using the (limited) space to contain as much content as possible.

Besides describing how to change settings via the Service Console CLI and the GUI, most tips also list PowerCLI and RemoteCLI example scripts. Incorporating PowerCLI scripts allows this book to be of value to the more experienced administrator who is using PowerCLI or RemoteCLI to manage its environment. The examples certainly increased my interest of picking up PowerCLI.

But what really makes this book shine is the short in-depth text accompanying most of the tips and how to’s. The text contains valuable information on how certain mechanism works, what impact changing a setting can have and field experience of using certain settings. Added bonus is addressing the possibility of using third-party tools such as Dell expart, EMC powerpath VE, vwire and many others, confirming that this book is written by authors with true field experience.

I really recommend this book to anyone who is using VMware ESX. It doesn’t matter if you are a novice administrator or a seasoned consulting architect, you WILL learn something new by reading this book. During the ESX 2.5 era, anyone who was serious about his job owned the Advanced Technical Design Guide, in the current vSphere era it’s clear that this book must be on your desk.

VMware updates Timekeeping best practices

A couple of weeks ago I discovered that VMware updated its timekeeping best practices for Linux virtual machines. December 7th VMware published a new best practice of timekeeping in Windows VMs. (KB1318)

VMware now recommends to use either W32Time or NTP for all virtual machines. This a welcome statement from VMware ending the age old question while designing a Virtual Infrastructure; Do we use VMware tools time sync or do we use W32time? If we use VMware tools, how do we configure the Active Directory controller VMs?

VMware Tools can still be used and still function well enough for most non time sensitive application. VMware tools time sync is excellent in accelerating and catching up time if the time
that is visible to virtual machines (called apparent time) is going slowly, but W32time and NTP can do one thing that VMware tools time sync can’t, that’s slowing down time.
Page 15 of the (older) white paper: Timekeeping in VMware Virtual Machines explains the issue.

However, at this writing, VMware Tools clock synchronization has a serious limitation: it cannot correct the guest clock if it gets ahead of real time (except in the case of NetWare guest operating systems).

For more info about timekeeping best practices for Windows VMs, please check out KB article 1318

It appears that VMware updated the Timekeeping best practices for Linux guests as well. (9 december 2009)

ESX 4i support Jumbo Frames

Last week I blogged about jumbo frames being unsupported in ESX 4i.
Yesterday Charu Chaubal, Sr. Technical Marketing Architect at VMware blogged the following;

I am happy to say that this is merely an error in the documentation. In fact, ESXi 4.0 DOES support Jumbo Frames on VMkernel networking interfaces. The correction will hopefully appear in a new release of the documentation, but in the meantime, go ahead and configure Jumbo frames for your ESXi 4.0 hosts.

Although Jumbo frames being unsupported might not be an adopion blocker, this is quite good news for companies willing to use ESX 4i.

Timesavers for VCDX application

Last week VMware send out the invitations for the VCDX defend session at the Partner Exchange Las Vegas 2010. Like many others I’m trying to finish my application on time. So any help, shortcut and timesavers will help realize the goal. At this moment these tools and shortcuts save me lots of time:

Steve miller created a simple but awesome tool. Puretext will strip any formatting while pasting text. This IS the lifesaver for me at the moment, because I’m copying text from older documents with different Fonttype and size. Run the small exe file and start loving the windows key + v command.

Visio shapes
Besides using graphics from the official VMware Branding Team, I also use visio shapes from the Xtravirt Presentation Pack 2.1. (needs registration)
Visiocafe will offer some really sweet vendor shapes, this will make your presentation look even more impressive 🙂

Visio shortcuts:

Align Shapes: F8
Duplicate: CTRL + D
Group: CTRL + G
Ungroup: CTRL + Shift + U
Fill: F3
Line format: ALT O L (ALT O = letter o)
Pointer tool: CTRL + 1
Text tool: CTRL + 2
Line tool: CTRL + 6
Rectangle tool: CTRL + 8
Centre Text: CTRL+Shift+C
Bring to Front: CTRL+Shift_F
Actual size: CTRL + Shift + i
Whole page: CTRL + W

If you have a tip, please feel free to comment

Impact of mismatch Guest OS type

During Healthchecks I frequently encounter virtual machines configured with the incorrect Guest OS type specified. Incorrect configuration of Guest OS of the virtual machine can lead to;

• Reduction of performance
• Different default type for the SCSI device *
• Different defaults of devices
• Wrong VMware Tools presented to the Guest OS resulting in failure to install
• Inability to select virtual hardware such as enhanced vmxnet, vmxnet3 or number of vCPUs.
• Inability to activate features such as CPU and Memory Hot Add.
• Inability to activate Fault Tolerance.
• VM burning up 100% of CPU when idling (rare occasions)

Buslogic SCSI Device
* Due to mismatch of Guest OS Type, windows 2000 and Windows 2003 can be configured with a Buslogic SCSI device. Using the Buslogic virtual adapter with Windows 2000 and 2003 will limit the effective IO queue depth of one. This limits disk throughput severely and lead to serious performance degradation. For more information visit KB article 1614

Virtual Machine Monitor and execution mode
Selecting the wrong Guest OS type can be of influence of the selected execution mode.
When a virtual machine is powering on, the VMM inspects the physical CPU’s features and the guest operating system type to determine the set of possible execution modes. This can have a slight impact on performance and in some extreme cases application crashes or BSODs.
VMware published a Must-Read whitepaper about the VMM and execution modes

How to solve the mismatch?
vCenter only displays the configured Guest OS of the Virtual Machine, it will not check the installed operating system inside the virtual machine. Powercli offers the solution to this problem, today more and more people start to discover the beauty of Powercli and incorporate this in their day-to-day activities.

So I’ve asked PowerCLI guru Alan Renouf if he could write a PowerCLI script which can detect the Guest OS mismatch.

Get-View -ViewType VirtualMachine | Where { $_.Guest.GuestFullname} | Sort Name |Select-Object Name, @{N=”SelectedOS”;E={$_.Guest.GuestFullName}}, @{N=”InstalledOS”;E={$_.Summary.Config.GuestFullName}} | Out-GridView

Alans “one-liner” checks the configured Gues Os Type in the VM (VM properties) and queries the VMtools to see which operating system it reports.

Once the mismatch is identified, set the correct Guest OS Type in the VM properties as soon as possible. The best way to deal with the mismatch is to power-down the VM before changing the guest OS type.

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