Was surprised this wasn’t here by default, but alas, out of the box vCO does not ship with a workflow to manage an NFS datastore.

Thanks to the VMware communities for a bit of scripting, I was able to put one together. First we’ll break out the components, then show you how it runs. Finally you’ll be able to pull it down.

Inputs:

So first we need to tell vCO where to find the NFS datastore as well as what host we are adding it to:

If you can’t read the above, no worries, I can’t either, so I’ve also got this handy table:

Name	Type	Description
Host	VC:HostSystem	Host to connect datastore to
DatastoreName	string	Name for Datastore
remoteHost	string	Hostname or IP for NFS server
remotePath	string	Path to Exports

Schema:

Now that we have our inputs, let’s build out the actual flow-charty bits for the workflow:

Yeah, pretty much that simple. Start, scripting block, stop.

Scripting!

Now for the awesomesauce that makes this work:

var datastore_mgr = Host.configManager.datastoreSystem;
 
var new_spec = new VcHostNasVolumeSpec();
new_spec.accessMode=VcHostMountMode._readWrite;
new_spec.localPath=DatastoreName;
new_spec.remoteHost=remoteHost;
new_spec.remotePath=remotePath;
new_spec.type=”nfs”;

try {
    var newDatastore=datastore_mgr.createNasDatastore(new_spec);
}

catch (ex) {
    System.log ( ex + ” creating datastore ” + remoteHost + “:” + remotePath + ” on ” + Host.name + ” as datastore ” + DatastoreName );
}

Note: Parts of this script were borrowed from the VMware communities here. Also found this here.

Running:

Results:

Summary

So, the workflow itself is kinda useful for a single host, it becomes more powerful when you embed it within another workflow to do say all hosts in a cluster. However, that’s an activity for the reader.

Download

The workflow can be downloaded from here!

More Info

We’ve talked about vCO extensively in the past… you can find some additional info here.

Since vSphere added the ability to have oddly numbered non power of two vCPU configurations, I’ve wondered what it’d be like to run a VM with an odd number. Will Windows react oddly? etc?

I also had some curiosity around doing similar for non standard amounts of ram (non power’s of two or multiples of 1024).

When changing resources on my vCenter VM I decided to take the plunge, Prime numbered CPU’s and 2PI * 1024 (rounded) MB of ram. Into it a few months now and so far so good!

So this happened. VMware has pulled the ESX Classic binaries from being available as a direct download:

While they do provide a download link for ESX classic, it sends a pretty clear message… If you haven’t made migration plans, NOW is the time to do so.

Thankfully, they’ve not left folks completely out to dry and have provided some basic ESXi migration guidance here.

Additionally, I’d suggest as a first step, installing ESXi as a VM inside VMware Fusion or Workstation to become familiar with it before migrating your production hosts. Like using Fusion/Workstation for other test/dev workloads, this should be no different. Test your tools, agents, processes, etc against the VM image before blowing away a production host.

Amazon posted my 4 star review of Ed Haletky’s (@Texiwill) updated VMware ESX and ESXi in the Enterprise.

Let me start with saying I’ve read the first edition of this book and Ed’s Security book and found both to be excellent.

As this book was a second edition, I focused my reading on those updated areas and there were a few. As always Ed provided a good balance between detail and real world examples/implementations that carry the weight of his experience with VMware on the whole.

I’d recommend this book for those getting into their first few ESX/ESXi implementations, and to supplement the official VMware courseware with real world examples.

All and all a good volume to get yourself going with some real world ESXi/vSphere implementation.

Maybe not in the fall out bunker sense ready, this isn’t Y2K all over again… not yet anyways.

Before the hysteria engine cranks up to full speed, I figured it was time to give you some tips to make sure you are ready. Note, I’m only going to cover making sure your ESX hosts are ready. There are plenty of resources out there for the remainder of your infrastructure.

Check your hypervisors to see if IPv6 is enabled:

Single Host – VI Client

1. Log into the VI Client
2. Select the host, then “Configuration”
3. Select “Networking”
4. Finally “Properties…”
   
5. In the resulting window lies your answer:
   

Single Host – CLI

1. esxcfg-vmknic -l
   

Single Host – PowerCLI

1. Get-VMHost | Get-VMHostNetworkAdapter | Select IPv6Enabled
   

Multiple Hosts – PowerCLI

# Generic e-mail script
#vCenters
$hosts = @(
    ""
);

$user = ""
$password = ""

# Connect to each vCenter & Check for hosts without IPv6
Connect-VIServer -Server $hosts -User $user -Password $password
$vmHosts = Get-VMhost
foreach ($vmhost in $vmhosts){
    if ( $vmhost | Get-VMHostNetworkAdapter -VMKernel | Where-Object {$_.IPv6Enabled -eq $false} ) {
        $effectedVMHosts += $vmhost.Name
    }
}
Disconnect-VIServer -Server $hosts -Confirm:$false   

Write-Host $effectedVMHosts

Before Going Forward:

There are a few critical bits to understand before going forward:

• IPv6 is “TEH Awesome” do not fear it.
• You will want to test this in a LAB First
• Before enabling it, you should realize the following:
• Enabling IPv6 will require a reboot, plan accordingly
• VMware HA and FT are not supported
• TSO (TCP Segment Offload) is not supported on IPv6
• IPv6 for IP Storage is “Experimental” for 4.0
• ESX 3.5 supports IPv6 for Guests

Enabling IPv6

Single Host – VI Client

1. Same steps as above.
2. Tick the box.
3. Reboot

Single Host – CLI

ESX

1. esxcfg-vswif -6 true
2. esxcfg-vmknic -6 true

ESXi

1. esxcfg-vmknic -6 true

Single Host – PowerCLI

Get-VMHostNetworkAdapter | where { $_.PortGroupName -eq "Service Console 1" } | Set-VMHostNetworkAdapter -IPv6Enabled $true

Multiple Hosts – PowerCLI

Get-VMHost | Get-VMHostNetworkAdapter | where { $_.PortGroupName -eq "Service Console 1" } | Set-VMHostNetworkAdapter -IPv6Enabled $true

Summary

The IPocalypse is coming, and it’s bringing it’s friends fear and hysteria with it. Wll you be ready? Hopefully with the above, you will have one less thing to worry about. If you have questions, comments, suggestions, or generally want to tell me to bugger off, drop a line in the comments, or follow me on Twitter here.

While this isn’t as big a problem as it used to be, Context Switches in applications can still bring a VM to it’s knees. In this post I’m going to link you to some resources as to what context switching is, how to look for it, and why excessive context switches hurts performance.

What Is Context Switching

• Wikipedia’s answer here.
• Linfo’s answer here.
• How they work on Windows.
• Seemingly, “Windows Internals 5th Ed” has some info in Chapter 5: “Processes, Threads and Jobs.”

Monitoring Context Switching

• On Windows – here and here.
• On Linux, you can use SAR:
• sar -w (more here)
• More on the Perfmon counters here.
• Page Faults (They cause context switches) on Windows here.

Why Excessive Context Switching Sucks

This, is likely the best post I’ve read on the cost of a context switch. Tsuna (the fellow from the first post) links to an excellent paper on some of the indirect costs also (here).

Virtualization
I was wondering how much overhead there is when using virtualization. I repeated the benchmarks for the dual E5440, once a normal Linux install, once while running the same install inside VMware ESX Server. The result is that, on average, it’s 2.5x to 3x more expensive to do a context switch when using virtualization. My guess is that this is due to the fact that the guest OS can’t update the page table itself, so when it attempts to change it, the hypervisor intervenes, which causes an extra 2 context switches (one to get inside the hypervisor, one to get out, back to the guest OS).

This probably explains why Intel added the EPT (Extended Page Table) on the Nehalem, since it enables the guest OS to modify its own page table without help of the hypervisor, and the CPU is able to do the end-to-end memory address translation on its own, entirely in hardware (virtual address to "guest-physical" address to physical address).

This bit, is important to note… newer generation processors (those with NPT) should not suffer the 2-3x increase in cost. However, they’re still expensive.

As always, if you’ve additional questions, please drop a note in the comments, or hit me up on Twitter.

The Problem!

Was doing some work with UDA and nested ESX & ESXi installs this weekend and ran into an interesting hiccup:

Or on ESXi:

What? Can’t format what? But we’re working with nested ESX, it’s a VMDK, format it! I tried any number of things here: Different controller types, disk sizes, partitioning within the kickstart file, etc. Nothing seemed to work. That is until I fired up Twitter and got a hint on the right direction from @hyperviz0r (http://www.hypervisor.fr/). He indicated that my problem may be related to NFS.

The Answer!

Sure enough, after some searching on the VMware forums, there are others out there with this problem. All of it seemingly related to nested ESX on NFS. I changed the build over to local storage on the ESX host and the install finished. I was also able to test successfully using iSCSI. I don’t have much in the way of explanation however, just that using another storage medium seems to work well.

You should follow me on twitter here. Or, leave a comment on the post!

There are times when you will need to put a host into, or take a host out of maintenance mode and you wont otherwise have the remote access needed to make PowerCLI or other API methods work. For times like those, vimsh works wonders:

This little gem comes from xtravirt:

To enter Maintenance Mode, at the ESX console type:
vimsh -n -e /hostsvc/maintenance_mode_enter

To exit Maintenance Mode type:
vimsh -n -e /hostsvc/maintenance_mode_exit

To display whether the ESX Server is currently in maintenance mode or not type:

vimsh -n -e"hostsvc/hostsummary" | grep inMaintenanceMode

This came up in the comments to one of my other posts, so I though I’d share.

Note: The Host Update Utility was depreciated with 4.1, so if you came here looking for that… my apologies.

The vSphere Host Update Utility, as far as I can tell is not actually offered as a separate download, but is rather bundled with the vSphere client and is a selectable option during installation. As admins most of us are trained to ignore these extra screens (after-all, who wants yet another Friendster toolbar installed?). This one is safe however, promise!

With vSphere comes the ability for third parties to add hardware to the HCL without having to wait for an update to ESX for their drivers to be included. An excellent move on VMware’s part as this opened up the door hugely for 3rd parties to supply certified & updated drivers as well as provide the ability to add hardware to the HCL between updates.

So when does one install these drivers? Well you have several opportunities, the first being during installation. The second, can be done post install using esxupdate.

Obtaining Drivers

First you will want to verify your hardware is indeed on the HCL by searching at http://www.vmware.com/go/hcl. Once verified, proceed to the downloads page for your edition of ESX, select “Drivers & Tools”, and then drill down for your specific drivers:

Installing Drivers

Now that you’ve downloaded the drivers, you will need to extract it and place the “offline-bundle” directory somewhere remotely accessible (http, ftp, nfs, or local):

user$ ls -al
total 168
drwxr-xr-x  4 user  staff    136 Jun  6 18:23 .
drwxr-xr-x  9 user  staff    306 Jun  6 18:23 ..
-rwxr-xr-x@ 1 user  staff  70842 Aug 17  2009 INT-intel-lad-ddk-igb-1.3.19.12.1-offline_bundle-185976.zip
-rwxr-xr-x@ 1 user  staff    271 Aug 17  2009 TRANS.TBL

There it is… now let’s install it. First, put the host into maintenance mode. Then fire up esxupdate to get it going:

[root@dbcfnhc1-vm ~]# esxupdate –bundle=http://professionalvmware.com/util/1000ET\ drivers/offline-bundle/INT-intel-lad-ddk-igb-1.3.19.12.1-offline_bundle-185976.zip update

Summary

This should have you covered for installing 3rd party drivers both during installation and after the fact (so long as it’s on the HCL). If you have any questions or comments, drop a line either in the comments or @cody_bunch on Twitter