Step by step guide for installing ESXi 6.0

Or, How to install VMware ESXi 6.0

Or, Installing VMware ESXi 6.0

Descriptions: Its not a big deal for experienced VMware administrators to install or upgrade ESXi server with any of the installation/upgrade methods but for friends who have just begin learning VMware, they may need to have a look at steps and options available to perform ESXi installation.

Yes, there are many ways of doing it, you can choose to do it with ISO if you have KVM supported on your hardware host, you can do it using VMware Update Manager, you can do it using CD/DVD drive attached with the physical hots etc..

In my scenario, I am using my lab environment to show you what all are the steps are there to complete the ESXi installation.

Steps: (installing ESXi hypervisor).

Boot your server with VMware ESXi 6.0 OS Disk or ISO image (in my case, I have VMware ESXi 6.0 Custom CISCO Installer) > Select the OS and hit Enter > Wait for the progress bar to be completed.

Hit Enter to continue when asked

Press F11 to accept the license terms and continue

Select the Installation storage/local storage and Hit Enter to continue

Select the desired language and hit Enter to continue

Press F11 to start the Installation

Wait for installation to be completed

Upon successful ESXi host installation, you may receive below message. Hit Enter to reboot the server.

After the reboot completion, you should be getting ESXi 6.0 DCUI like below. From this window onward, you can do the ESXi configuration you wish e.g. network, DNS etc configurations.

Cheers, Please write me back if you have any query of feedback on this..

VMware converter tool error “The File System On "Datastore1" Does Not Support File This Large. Please Check the File System Block Size.”

Or, P2V conversion error “the file system on datastore1 does not support file this large. please check the file system block size.”

Descriptions: This error was encountered while performing P2V conversion of a Physical server containing large storage capacity (more than 6-7 TB of drive capacity).

The error screenshot (how it looks like):

Possible reasons of this error:

1. One of the volume size on this server is more than 2TB (Here I am referring to whole Volume Size of one of the RAID volume configured in this server on hardware level).

Example:  It’s possible that one of the RAID volume on your physical server is having 4TB of total capacity. This 3TB RAID volume may have multiple logical disk partitions inside the OS e.g. D, E, F etc…).

2. The VMware Converter tool you are using is not the latest one as per your VMware vSphere Infra.

Solution/Workaround:

1. Use latest version of VMware Converter tool.

2. Instead of default option, use Advance Feature of Data Copy Type Selection

3. Use only occupied disk conversion method selection. To do this, you can edit data copy option (shown in error screenshot) and choose only occupied disk. Don’t be afraid, you can easily increase the partitions size once this physical machine is converted in Virtual Machine.

Cheers, if you have any query or feedback, please write me back...

VM shutdown when performing snapshot restore in VMware vSphere.

Or, VM shutdown automatically when restoring to previous snapshot restore point.

Descriptions: This not an error… Its normal behaviour of Virtual Machine snapshot restoration feature. Depending upon the state when the snapshot was taken, virtual machine will go to that state while performing the snapshot restore.

Example-1: If the Virtual Machine is Powered On and you have taken a snapshot in this state, this is not going to reboot or shutdown the VM when you perform the Revert Snapshot task from Snapshot manager.

Example-2: If you the Virtual Machine is Powered Off and you have taken a snapshot in this state, this is going to shutdown the Virtual Machine when you perform the Revert Snapshot task from snapshot manager.

Note: No worries, in both conditions you should be able to get your VM up and running. If the VM get powered off while performing the snapshot restore, you can just power it on soon after the snapshot restore operation is completed successfully.

Cheers, If you have any query of feedback on this, please write me back..

Understanding, Zeroing, Lazy Zeroed, Eager Zeroed, and Thin Provision concepts in VMware vSphere.

Or, VMware Disk Provisioning Concepts about Lazy Zeroed, Eager Zeroed and Thin Provision.

Or, Lazy Zero Vs Eager Zero Disk Provisioning.

Or, Difference between Thick Provision Lazy Zeroed, Thick Provision Eager Zeroed, and Thin Provision Disk Provisioning.

Zeroing

Before the VM can actually use the allocated drive space, there are some operations that take place on ESXi host level. When you allocate a disk space from your Datastore, Datastore also maintain itself to allocate that amount of Disk space with clean/formatted sectors.

This disk sectors cleaning process is basically referred as Zeroing term. As you do disk formatting at Guest level to make it ready to use, the same task is performed by ESXi Host at Datastore level when you add any partition/disk to a VM from any Datastore.

Thin Provisioned Disk: Allocate and zeroed on first write. When you create a disk with thin provisioning method, it only writes a small amount of metadata to the Datastore where it resides. When the write operation is performed, vSphere first updates the allocation metadata of the VMDK, then zeros out the blocks, lastly it writes the data. Thin provisioned VMDKs have the lowest performance logically at some points.

Once the Zeroing is completed for allocated disk blocks, almost all disk types performs equally.

Thick Provisioned Lazy Zeroed Disk: Allocate in advance and zero on first write. Do nothing to empty blocks, it zeros all the blocks at first access... Provisioning of this disk type is little faster than other disk type. Performance of this disk type is slower than Eager Zeroed Disk type and it is not supported for clustering.

Example: If you have 10GB disk size and having only 5GB data in it, then 5GB will be zeroed at first access, rest 5GB will be left.

Thick Provisioned Eager Zeroed Disk: Allocate and zero in advance. Writes 0 to empty blocks. Write is performed on whole allocated disk.  Means, its pre-zeroing all the blocks on the disk. Performance of this disk type is better than all others but provisioning time may take little longer than other disk types. It also supports clustering features.

Example: If you have 10GB disk size and have only 5GB Data in it, then 5GB will be used and rest 5GB will be written with 0. No further Zeroing is required while any write operations.

Cheers, Please write me back if you have any query or feedback on this..

Understanding Thick Provisioning and Thin Provisioning in VMware

Or, Difference between Thick Provisioning and Thin Provisioning in VMware

Or, How Think Provisioning and Thin Provisioning works in VMware

Descriptions: Thin Provisioning disk allocation method in VMware vSphere is one of the cool feature to use your storage to a limit beyond the storage capacity limit… There are some pros and cons of each provisioning method whether it is Thick or Thin but it’s all depends on your requirement and criticality of servers and how you want to use it.

e.g. For database servers, I rarely think of allocating Thin Provisioned Disk. Because, Database log files and even Database can increase anytime drastically and if you don’t have enough free space on the respective Datastore, This VM will go in Answer mode (its equal to down till the time you fix it).

Thick Provisioning: This provisioning refer to disk provisioning method where all the allocated disk space is occupied by the Virtual Machine.

Example: When you allocate 40GB drive space to a Virtual Machine with thick provisioning method, it reserves all 40GB allocated disk space from your Datastore. Even if the VM is having 10GB of data inside that drive, it will take complete 40GB space from the associated Datastore. There are further two type of thick provisioning, Lazy Zeroed and Eager Zeroed.

Thin Provisioning: This provisioning method refers to disk provisioning method where only used space is occupied by the Virtual Machine.

Example: When you allocate 40GB drive space to a virtual machine with thin provisioning, it does not reserve the complete 40GB allocated disk space from your Datastore. If your VM is using only 10GB of out of 40GB allocated drive space, then thin provisioning helps remaining free 20GB disk space to be released from that particular VM. Means, no matter how much drive space you have allocated for your VM, it will utilize only what it required.

You can try it by assigning 40GB drive space with Thin Provisioning method to any VM even if you have 30GB of drive space free in your Datastore. It will allow you to do so.

Reference screenshot-1: I have 20GB free space in Datastore and adding a Disk with 40GB capacity to my Test-VM-1 with Thick Provisioning Method.

If you will dare to go with this option, you are going to end up with below error.

Reference Screenshot-2: I have 20GB free space in Datastore and adding a Disk with 40GB capacity to my Test-VM-1 with Thin Provisioning Method.

 Cheers, please write me back if you have any query or feedback on this…

How Limit, Shares and Reservation works in VMware?

Or, Understanding Limit, Reservation and Shares in VMware.

Or, How to use VMware Virtual Machine’s resources features Limit, Shares and Reservations

Descriptions: For small VMware Infrastructure, these features may not be so important to consider but in large scale VMware Infrastructures these features play very crucial roles in managing different type of Servers and applications depending on their nature criticality and availability commitments.

Virtualization is a platform where we forget about most of limitations that exist at hardware level, but it means not that we should forget about limitations of Virtualization.

In Virtualization, we over provision the resources being it CPU or RAM and just to keep your critical applications and servers safe from over provisioning caused contention scenarios, these features of resources allocation come in to the picture.

Let’s see this example below:

In the above, example you have One ESXi Server, with 40 Logical CPUs after enabling HT on the Physical CPU and you have 20 Virtual Machines each having 4 vCPUs allocated. So, now if you will calculate the total allocation of vCPUs, its 20*4=80. Imagine, you have only 40 logical CPUs at ESXi Host level but you have allocated just double number of vCPUs to your Virtual Machines.

Its real that, all of these Virtual Machines will work well as per the Virtualization concept, but the Situation will be just opposite if in case at any point of time, all VMs demand their complete allocations. ESXi host going to be dead due to contentions.. J

So, here my friends you still have a chance to keep your CRITICAL VMs alive if this situation occurs in your environment. Yes, you are right... You have to use the Reservation, Shares and Limit features here…

Let’s see how…….

Limit: Limit means Limit...that a Virtual Machine can be entitled for. You can define limit at both CPU or Memory level. Memory limit defines the maximum capacity of physical memory that a Virtual Machine can use. Same way, CPU limits defines the maximum capacity of CPU can be used by a VM.

Memory Limit: Be careful while settings up memory limit as setting it up wrongly may drastically decrease the performance of the Virtual Machine.

Example: If you have allocated 8GB RAM to a VM, and have set the limit of 4GB, this VM is going to give you very slow performance as it will not be able to get required resources when in need.  Inside Guest OS, its 8GB RAM but on top of it its only 4GB what ESXi will allow this VM to use.

Now, this VM will create ballooning and multiple vMotions among available hosts.

CPU Limit: Likewise, RAM limit, CPU limits also limits the CPU resources that a VM can use. Even if the Resources are available on the base ESXi host, the Virtual Machines sets with certain limits can’t go beyond the defined limit for them. In some cases, its useful but in most of the cases ESXi is intelligent enough to manage how much resources should be given to which VMs.

You can use this method more practically on Development of Test Servers where you may need to assign more CPU account to a VM but can limit the usage of allocated CPUs when work test/development is done.

Share: By default, Shares are equally distributed among Virtual Machines. The reason shares are equally distributed is, VMware does not know which Virtual Machine is important for you. So, it treated all your Virtual Machines equally important.. J

Shares defines, which Virtual Machine is going to have priority to be kept alive with enough resource allocation in any kind of contentions in VMware Infrastructure.

Example: If you have two VMs (VM-1 and VM-2) and both having shares value 1000, means the ESXi host will allow both of them to use 50% of available resources in case of any contention.

If there is no contention and no VMs are struggling for resources, no shares will come in to the picture. Shares are to prioritize the VMs resources availability in case of resources crunch.

Let’s see the below calculations, how shares will work in case of contentions if two VMs are struggling for resources on the same ESXi Host.

Reservations: Reservation defines the amount of resources that remains reserved forever for the Virtual Machine. This is majorly used in most CRITICAL VMs where you can’t compromise to slow down the performance of the Virtual Machine in any case.

Reservation helps a VM to reserve the specified amount or resources whether it’s being used or not. Even if contention situation pop-ups, the Virtual Machine will be having its reserved resources.

Example: If you have a VM with 8GB memory and you have set the reservation of 4GB, This VM will reserve 4GB memory always. When contention occurs, this VM will have at least 4GB of memory to ensure the applications in this server are having enough compute to perform well.

If there is no contention and this VM requires 8GB of memory, it can use it. Because, the allocated memory size of the Virtual Machine is 8GB.

Cheers, please write me back if you have any query or feedback on this...

VMware vSphere Comparisons 5.5 vs 6.0 vs 6.5 vs 6.7 at one place

Or, What all are the major capacity supporting changes or enhancements across VMware vSphere 5.5, 6.0, 6.5, and 6.7.

Or, Major maximums differences of VMware vSphere 5.5, 6.0, 6.5, and 6.7

Descriptions: As the new release 6.7 of VMware vSphere is out in the market, it’s important for you to check out what all are the major capacity support enhancements or changes are done in this release before you think of upgrading your current ESXi Infra to any of the next releases.

In this article, I will take through some major difference within vSphere version 5.5, 6.0, 6.5, and 6.7. This article is focused on checking out capacity enhancement/maximums and not covering other enhancements and features which may be ESXi OS level, Graphics or etc... I tried consolidating some data points from all datasheets of vSphere Maximums which really effects each level of VM Infra.

Here are the comparisons

Updated: 02/05/2017
There may be some further maximum and minimum supported capacity of ESXi hosts and other VMware components. To know more in-depth and explore all possible segregation of supported capacity limits, please refer the below VMware KB:
https://kb.vmware.com/1003497

Updated: 02/01/2019
Added vSphere 6.7 in the list of comparison.

Cheers, please write me back if you have any query or feedback on this…