Search Results for: kickstart

Quick Tip - How to enable "remote" disk for Nested ESXi?

08.13.2014 by William Lam // Leave a Comment

I always love to hear about new tips and tricks from Internal VMware folks, especially ones that I can share with the community. The other day, my colleague Paudie O'Riordan had a pretty interesting problem that he was trying to solve pertaining to a re-production he was helping out with. After he found the solution, he thought I might find it interesting and he shared the details with me.

Paudie was looking for a quick way to force a disk to show up as "remote" versus "local" in a Nested ESXi VM during the installation process.

The disk type will depend on how the disk was presented to the ESXi host, but sometimes even local devices may show up as remote, especially if the disk controller is not in pass-through mode. Instead of having to setup a complex iSCSI setup, Paudie found that if you selected LSI Logic SAS as the virtual SCSI Disk Controller for your Nested ESXi VM instead of the default LSI Logic Parallel, that automatically any disks placed on that controller will automatically show up as remote.

This is definitely a handy tip you may want to bookmark, especially if you are looking to test any type of Kickstart configuration where you may be dealing with remote devices or practicing for your VCP/VCAP exams and playing with ESXCLI claim rules.

Does VSAN work with Free ESXi?

07.22.2014 by William Lam // 8 Comments

I recently had to re-provision one of my VSAN lab environments using my recently shared ESXi 5.5 VSAN Kickstart. I usually specify a license key within the Kickstart so I do not have to license the ESXi host later. This actually got me wondering on whether VSAN would in fact work with Free ESXi aka vSphere Hypevisor? Being a curious person, I of course had to test this in the lab 🙂

Needless to say, if you want to properly evaluate or use VSAN in production, you should go through the supported method of using vCenter Server as it provides a simple and intuitive management interface for VSAN. More importantly, having the ability to create individual VM Storage Policies that can be applied on a per VMDK basis based on SLA's for your given application or Virtual Machine.

Disclaimer: This is not officially supported by VMware and running ESXi without a VSAN license is against VMware's EULA.

Since we do not have a vCenter Server, we will need to be able to fully configure VSAN without it. Luckily, we know of a way to "bootstraping" VSAN onto an ESXi host without vCenter Server and I will be leveraging that blog post to test this scenario with Free ESXi.

Prerequisite:

3 ESXi 5.5 hosts already installed and licensed with vSphere Hypervisor (Free ESXi) License
SSH Enabled

Step 1 - SSH to the first ESXi host and run the following ESXCLI command to create a VSAN Cluster:

esxcli vsan cluster join -u $(python -c 'import uuid; print str(uuid.uuid4());')

Step 2 - Run the following ESXCLI command to make a note of the VSAN Cluster UUID (highlighted in green in the screenshot above) which will be needed later:

esxcli vsan cluster get

Step 3 - Enable VSAN Traffic for VMkernel interface you plan on using for VSAN traffic by running the following ESXCLI command:

esxcli vsan network ipv4 add -i vmk0

Step 4 - Run the following command to view a list of disks that are eligible for use with VSAN. You will need a minimum of 1xSSD and 1xMD

vdq -q

Step 5 - Using the information from vdq, we will now create our VSAN Disk Group which will contain the SSD/MD's to be used for VSAN. Use the following ESXCLI command and substituting in the SSD/MD Names (please refer to the screenshot above for an example):

esxcli vsan storage add -s [SSD] -d [MD]

Step 6 - To ensure you have properly configured a VSAN Disk Group, you can run the following ESXCLI command to confirm:

esxcli vsan storage list

At this point, we now have a single ESXi host configured with VSAN Datastore, we can also confirm this by running the following ESXCLI command:

esxcli storage filesystem list

Step 7 - Repeat Steps 3-6 on the remainder two ESXi hosts

Step 8 - Finally, we now need to join the remainder ESXi hosts to the VSAN Cluster. We will need the VSAN Cluster UUID that we recorded earlier and specify that in the following ESXCLI command on each of the remainder ESXi hosts:

esxcli vsan cluster join -u [VSAN-CLUSTER-UUID]

If we now login to all of our ESXi hosts using the vSphere C# Client, we will see a common VSAN Datastore that is shared among the three ESXi hosts. To prove that that VSAN is in fact working, we can create a Virtual Machine and ensure we can power it on as seen in the screenshot below. By default, VSAN has a "Default" policy which defines FTT (Number of host failures to tolerate) set to 1 and assuming you have at least 3 ESXi hosts, all Virtual Machines will be protected by default.

Even though you can run VSAN using Free ESXi and leveraging the default VM Storage Policy that is built into VSAN for protecting Virtual Machines, you are only exercising a tiny portion of the potential that VSAN can bring when consuming it through vCenter Server. As mentioned earlier, you will not have the ability to create specific VM Storage Policies and assign them based on the specific SLAs and be able to easily monitor their compliance and remediation. The management of VSAN Cluster for adding additional capacity or serviceability is also quite limited without vCenter Server, though it can be definitely be done it is much easier with just a couple of clicks in the vSphere Web Client or a simple API call.

How to properly clone a Nested ESXi VM?

12.06.2013 by William Lam // 53 Comments

I often hear from users that they would like to be able to just clone from an existing Nested ESXi VM that has already been configured and just create additional Nested ESXi VM instances from that. For me personally, I do not have a use case for this since I just deploy additional ESXi instances using an automated Kickstart deployment. However, I can see why this would be useful for anyone that does not have an automated deployment or just want to quickly deploy additional Nested ESXi instances by just cloning from an existing image and then manually change the networking configuration afterwards.

UPDATE (07/01/21) - As of ESXi 7.0 Update 2, cloning an ESXi boot volume (Nested or Physical) is no longer safe and can lead to data corruption. Please refer to the following two VMware KB articles for more information on this topic https://kb.vmware.com/kb/84280 and https://kb.vmware.com/kb/84349

First off, cloning of a Nested ESXi VM is possible and you can already do this today. You will get a brand new Virtual Machine that will have a unique MoRef ID, InstanceUUID, BIOS UUID and MAC Addresses for each of the virtual network adapters which you can see an example of this from the screenshot below.

Everything from outside of the guest OS looks great as we would expect but there is actually two issues from within ESXi that you may not be aware of.

The first issue is that you will get a duplicated MAC Address of the VMkernel interface(s) because the Nested ESXi configuration is exactly the same.
The second issue is having a duplicated ESXi System UUID, also known as a VMkernel UUID which should normally be unique and can sometimes be used for tracking purposes. You can see this System UUID by running the following ESXCLI command: esxcli system uuid get or by looking in esx.conf configuration file.

To properly clone an existing Nested ESXi VM, you will need to perform the following two operations within the Nested ESXi VM prior to cloning.

First Configuration - There is an advanced ESXi setting called FollowHardwareMac that will automatically update the VMkernel's MAC Address whenever the Virtual Machine's virtual network adapter MAC Addresses changes. To do so, you will need to run the following ESXCLI command:

esxcli system settings advanced set -o /Net/FollowHardwareMac -i 1

Second Configuration - The other modification that is required is to delete the existing System UUID entry in /etc/vmware/esx.conf configuration file. This will ensure a new System UUID will automatically be generated when the system boots up. To do so, open esx.conf and delete the entire /system/uuid line entry as seen in the screenshot below. Here is a quick snippet you can run without needing to open up VI:

sed -i 's#/system/uuid.*##' /etc/vmware/esx.conf

To ensure the file is persisted, run /sbin/auto-backup.sh

Once both configurations have been performed you are now ready to start cloning additional Nested ESXi instances. You will still need to login to each Nested ESXi VM and manually change the IP Address and hostname which you of course can leverage the Guest Operations API if you have VMware Tools for Nested ESXi installed.

If you plan on joining your "cloned" Nested ESXi instances to a vCenter Server and the ESXi hosts contains a local datastore, you will not be able to add the hosts to the same Datacenter/Cluster. The reason for this is that the cloned ESXi hosts will have a duplicated VMFS UUID. To fix this, you just need to re-signature the VMFS volume by using the following ESXCLI command:

esxcli storage vmfs snapshot resignature -l [VMFS-VOLUME]