WilliamLam.com

How to Create Bootable ESXi 5 ISO & Specifying Kernel Boot Options

by // 20 Comments

This week I helped to answer a few questions about creating your own ESXi 5 bootable ISO along with automatically using a static IP Address when the custom ISO first boots up. Although all this information is available via the vSphere documentation, it may not always be easy to put all the pieces together and thought I share the steps for others to also benefit.

You will need access to a UNIX/Linux system and a copy of the base ESXi 5 ISO image. In this example I will be using VMware vMA and VMware-VMvisor-Installer-5.0.0.update01-623860.x86_64.iso and walk you through two different configurations. We will also be referencing the vSphere documentation Create an Installer ISO Image with a Custom Installation or Upgrade Script and Kernel Boot Options.

Create ESXi 5 Bootable ISO w/Remote ks.cfg:

In this configuration, we will create a custom ESXi ISO that will boot with a static IP Address and use a remote ks.cfg (kickstart) configuration file.

Step 1 - Mount base ESXi ISO using the "mount" utility:

$ mkdir esxi_cdrom_mount
$ sudo mount -o loop VMware-VMvisor-Installer-5.0.0.update01-623860.x86_64.iso esxi_cdrom_mount

Step 2 - Copy the contents of the mounted image to a local directory called "esxi_cdrom":

$  cp -r esxi_cdrom_mount esxi_cdrom

Step 3 - Unmount the ISO after you have successfully copied it and change into the esxi_cdrom directory

$ sudo umount esxi_cdrom_mount
$ cd esxi_cdrom

Step 4 - Edit the boot.cfg and specifically the "kernelopt" line to not use the weasel installer but kickstart and also specifying the remote location of your ks.cfg. To get more details on the various kernel boot options, please take a look at the vSphere Boot Options documentation above.

You will also need to specify the static IP Address you wish to have the host automatically use when the ISO first boots up on the same line.

Step 5 - Once you have finished your edits and saved the boot.cfg, you will now change back to the parent directory and use the "mkisofs" to create your new bootable ISO. In this example, we will name the new ISO "custom_esxi.iso":

$ sudo mkisofs -relaxed-filenames -J -R -o custom_esxi.iso -b isolinux.bin -c boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table esxi_cdrom/

You now have a new bootable ESXi 5 ISO called "custom_esxi.iso" which will now automatically boot up with the specified static IP Address and install based on the ks.cfg that was specified.

Create ESXi 5 Bootable ISO w/Local ks.cfg:

Similar to the above configuration, we will create a custom ESXi ISO that will boot with a static IP Address but use a local ks.cfg (kickstart) configuration file that will be included within the custom ISO.

Step 1 through 3 is exactly the same as above

Step 4 - By default, a basic ks.cfg is included in the ESXi 5 ISO in /etc/vmware/weasel/ks.cfg and we will create a custom *.tgz file that will include our ks.cfg within the ISO. First off by creating a temporary directory which will be used to store our ks.cfg:

$ mkdir -p temp/etc/vmware/weasel

Step 5 - Copy your ks.cfg file into the temp/etc/vmware/weasel:

$ cp ks_custom.cfg temp/etc/vmware/weasel

Step 6 - Create a *.tgz file containing the path to our ks.cfg using the "tar" utility. In this example, we will called it customks.tgz:

$ cd temp
$ tar czvf customks.tgz *

Step 7 -  Copy the customks.tgz from temp directory to your esxi_cdrom directory:

$ cp temp/customks.tgz esxi_cdrom

Step 8 -  Change into the "esxi_cdrom" directory and edit the boot.cfg just like the above, but we will be using the "file://" stanza to specify the path to our ks.cfg, static IP Address as well as adding our customks.tgz to the module list to ensure that it loads up which contains the actual ks.cfg file that is called in the boot.cfg.

Step 9 - Same as Step 5 above, you now just need to run the "mkisofs" utility to create your bootable ISO.

You now have a new bootable ESXi 5 ISO called "custom_esxi.iso" which will now automatically boot up with the specified static IP Address and install based on the ks.cfg that is included within the ISO.

VM Provisioning on Datastore Clusters in vSphere 5

by // 23 Comments

Last year I wrote an article called Automating Storage DRS & Datastore Cluster Management in vSphere 5 and I provided a pretty comprehensive vSphere SDK for Perl script to help administrators automate Storage DRS configurations. These past few months I have noticed an increase in interest on the VMTN developer forums relating to Storage DRS. Majority of the questions has been related to which vSphere API methods to use and how to use these methods for cloning VMs to datastore clusters.

If you have cloned a VM before, the underlying vSphere API method being used is the CloneVM_Task(), but when cloning a VM to a datastore cluster, a different API must be used.

In vSphere 5, VMware introduced several new API methods in the StorageResourceManager and the two specific ones relating to provisioning VMs are RecommendDatastores() and ApplyStorageDrsRecommendation_Task(). The process to clone a VM to a datastore cluster is a two step process:

  1. Call RecommendDatastores() which accepts very similar input as the CloneVM_Task(). In addition, you need to specify the datastore cluster also known as a Storage Pod in the vSphere API as well as the "type" (create, clone, relocate, reconfigure), in this example we will be performing a clone operation. This method will then generate a recommendation on where to place the VM which is based on the SDRS placement engine. No provisioning will occur at this point, just a placement recommendation.
  2. To perform the actual provision of the VM, you will need to call ApplyStorageDrsRecommendation_Task() which accepts a recommendation ID that was generated from the first step. Once the recommendation is applied, the provisioning of the VM will start just like it did when you called the CloneVM_Task().

Note: The RecommendDatastores() will return multiple recommendations, the best one will be first entry in the array. This is the same algorithm used when performing this same operation in the vSphere Client, it also selects the first recommendation.

Now that we understand how the APIs work, let's take a look at how we can leverage this in a script for some automation! Here is a simple vSphere SDK for Perl script called datastoreClusterVMProvisioning.pl which allows you to clone an existing VM onto a datastore cluster. You will need a system that has vCLI 5.0 installed or you can use VMware vMA 5 to run the script. You will also need to connect to a vCenter Server 5 for all SDRS operations.

The script requires 4 input parameters:

  • vmname - Name of the VM you wish to clone from
  • clonename - Name of the cloned VM
  • vmfolder - Name of a vCenter folder
  • datastorecluster - Name of a datastore cluster

Here is a screenshot of cloning an existing VM onto a datastore cluster:

The script is pretty straight forward and it can easily be adapted to include other configurations as required in your own environment.

Hopefully this gives you a better idea on how to leverage the new provisioning APIs for Storage DRS and start automating your VM deployments onto datastore clusters and get the benefits Storage DRS in your vSphere environment.

How to Deploy an OVF Located On ESXi Datastore Using ovftool

by // 43 Comments

I have written several articles in the past about the awesome ovftool which is a versatile remote command-line utility for importing/exporting virtual machines in the OVF format across various VMware products. I mainly run ovftool in either the vMA or on my OSX desktop. When performing an import, the OVF files are local on the same system that has the ovftool installed.

I recently came across an interesting question about using the ovftool to deploy OVF files that are located on an ESXi datastore. My initial thought was that you would not be able to deploy the OVF files since the ovftool would not have access to the files locally. After finishing a recent article about ESXi datastore management using the vCLI's vifs utility, I then realized there might actually be a way to deploy OVF files that are stored on an ESXi datastore.

If you take a look on page 17 of the ovftool user guide, there is a table describing the various source locators that are supported. You can see that the source of an OVF file can be accessed by ovftool in 4 different methods including HTTP/HTTPs which is a key for this specific request.

Source Type Default File Extension Protocol
OVF .ovf File, HTTP, HTTPS, FTP
OVA .ova File, HTTP, HTTPS, FTP
VMX .vmx File
vvApprun N/A File
vCloud Director N/A HTTPS
vSphere N/A vSphere

Files and folders management for a datastore is exposed through the fileManager in the vSphere API and datastores are referenced as a URL or remote path.

A URL has the form

scheme://authority/folder/path?dcPath=dcPath&dsName=dsName

where

  • scheme is http or https.
  • authority specifies the hostname or IP address of the Center or ESX(i) server and optionally the port.
  • dcPath is the inventory path to the Datacenter containing the Datastore.
  • dsName is the name of the Datastore.
  • path is a slash-delimited path from the root of the datastore.

Putting all this together, you can use the ovftool remotely to deploy an OVF file that is stored on an ESX(i) datastore. Below is an example walk through of this process.

Here is an OVF that is stored on a datastore located on an ESXi host:

To identify the URL path to your OVF, you can use a web browser to assist. Point your browser to the following address: https://[ESXI_HOST]/folder

When you first login, you will be brought to the root datacenter, in the case of directly connecting to an ESX(i) host, you will only see "ha-datacenter". Go ahead and select it and then you will be brought to a list of datastores the host has access to.

Select the datastore which contains the OVF file you wish to deploy from and then browse to the specific file.

Make a note of the URL path used to get to the OVF file and the OVF filename itself. Taking the example above, we end up with the following URL path:

https://vesxi50-4.primp-industries.com/folder/MyVM/MyVM.ovf?dcPath=ha-datacenter&dsName=iSCSI-1

To confirm the URL path, we can use ovftool to perform a simple "probe" on our OVF, this will provide you with a quick summary of the OVF.

Next we are ready to import the OVF file to our ESXi host. In this example, we will deploy the OVF to another datastore the ESXi host has access to and configure a specific portgroup to connect to the VM to after deployment. There are various options that can be passed to ovftool, please refer to the ovftool user guide for more details.

One the import has completed, you should now see the VM automatically registered in your ESXi host inventory.

You can see that this method allows you to import an OVF file stored on a datastore locally to the ESXi host as well as an OVF file stored on a remote datastore of another ESXi host. To help manage and deploy your OVF files, you should consider storing them on a centralized "media" datastore or even a WEB/FTP server that can be accessed by the ovftool.