Category: Virtualization_2019

ESXi is the hypervisor in a vSphere environment. The hypervisor provides physical hardware resources dynamically to virtual machines as needed to support the operation of the virtual machines. The hypervisor allows virtual machines to operate with a degree of independence from the underlying physical hardware. For example, a virtual machine can be moved from one physical host to another, or its virtual disks can be moved from one type of storage to another, without affecting the functioning of the virtual machine.
Because virtual machines are decoupled from specific underlying physical hardware, virtualization allows you to consolidate physical computing resources such as CPUs, memory, storage, and networking into pools of resources that can be dynamically and flexibly made available to virtual machines. With appropriate management software, such as vCenter Server, you can also use a number of features that increase the availability and security of your virtual infrastructure.

VSAN 6.6 : New Features

tapasmahanta1241 Comment

VMware vSAN release was just announced, namely vSAN 6.6

There are many new features which were pushed on the latest release ,few of them are listed below:

1: vSAN Encryption : 

Encryption in vSAN 6.6 takes places at the lowest level, meaning that you can also get the benefits of dedupe and compression. vSAN encryption is enabled at the cluster level, but It is implemented at the physical disk layer, so that each disk has its own key provided by a supported Key Management Server (KMS).For customers running all-flash vSAN however there was one big disadvantage and that is that encryption happens at the highest level meaning that the IO is encrypted when it reaches the write buffer and is moved to the capacity tier.

vCenter instance object –> Configure tab –> More / Key Management Servers.

2: Local Protection in vSAN Stretched Cluster : 

There are now two protection policies; Primary level of failures to tolerate (PFTT) and Secondary level of failures to tolerate (SFTT). For stretched cluster, PFTT defines cross site protection, implemented as RAID-1. For stretched cluster, SFTT defines local site protection. SFTT can be implemented as RAID-1, RAID-5 and RAID-6. 

3: Unicast Mode :

If you are upgrading from a previous version of vSAN, vSAN will automatically switch to unicast once all hosts have been upgraded to vSAN 6.6. Now there is a catch to it ,if the on-disk format has not been upgraded to the latest version 5, and a pre-vSAN 6.6 host is added to the cluster, then the cluster reverts to multicast.Here is what you see through the client:

Command you can use is : 

esxcli vsan cluster unicastagent list

4: Resync Throttling :

In the past, if a resync process was interrupted, the resync may need to start all over again. Now in vSAN 6.6, resync activity will resume from where it left off (if interrupted) by using a new resync bitmap to track changes.

5: pre-checks for maintenance mode :

It point out on the data present in the disk group.

Warning message : Data on the disk from the disk group xxxxxxxxx will be deleted . Unless the data on the disks is evacuated first,removing the disks might disrupt working VMs.

Three options but it has all the information in details what we need to understand:

  • Evacuate all data to other host — > It will let you know the amount of data that will be moved to other hosts .
  • Ensure data accessibility from other hosts –>No data will be moved
  • No data evacualtion –> No data will be moved form the location.

6: HTML5 Host Client Integration :

This one is the best and was much awaited feature on VSAN.

For more reference please follow :

 

New esxcli commands for VSAN

tapasmahanta1241 Comment

A new esxcli command to assist with troubleshooting has also been added:

esxcli vsan debug
Usage: esxcli vsan debug {cmd} [cmd options]

Available Namespaces:

 disk Debug commands for vSAN physical disks
 object Debug commands for vSAN objects
 resync Debug commands for vSAN resyncing objects
 controller Debug commands for vSAN disk controllers
 limit Debug commands for vSAN limits
 vmdk Debug commands for vSAN VMDKs

As well as the esxcli vsan debug command, we also added the following commands in vSAN 6.6 information to get troubleshooting information:

 • esxcli vsan health cluster
 • esxcli vsan resync bandwidth
 • esxcli vsan resync throttle
 • esxcli vsan cluster unicastagent list
Example 1:
++++++++++
Use "vsan debug vmdk" command to check all of VMDKs status:
 
 [root@TestVSAN:~] esxcli vsan debug disk list
 UUID: 52bc7654-xxxx-xxxx-xxxx-54cf6cda4368
    Name: naa.xxx
    SSD: True
    Overall Health: green
    Congestion Health:
          State: green
          Congestion Value: 0
          Congestion Area: none
    In Cmmds: true
    In Vsi: true
    Metadata Health: green
    Operational Health: green
    Space Health:
          State: green
          Capacity: 0 bytes
          Used: 0 bytes
          Reserved: 0 bytes
 
Example 2:
++++++++++
 [root@TestVSAN:~] esxcli vsan cluster unicastagent list
NodeUuid IsWitness Supports Unicast IP Address Port Iface Name
------------------------------------ --------- ---------------- ------------- ----- ----------
52e8ac54-xxxx-xxxx-xxxx-54cf6cda4368 0 true 10.10.0.111 12321
52e8ac78-xxxx-xxxx-xxxx-98cf6xas5345 0 true 10.10.0.112 12321
52e8ac21-xxxx-xxxx-xxxx-56ab6cba4368 0 true 10.10.0.113 12321

PowerShell Modules for Rubrik

tapasmahanta1241 Comment

So once you connect to the Rubrik Module :

Requirements:

  1. PowerShell version 4 or higher
  2. PowerCLI version 6.0 or higher
  3. Rubrik version 2.2 or higher
  4. (optional) Windows Management Framework 5.0 

Installation :

+++++++++

  1. Ensure you have the Windows Management Framework 5.0 or greater installed.
  2. Open a Powershell console with the Run as Administrator option.
  3. Run Set-ExecutionPolicy using the parameter RemoteSigned or Bypass.
  4. Run Install-Module -Name Rubrik -Scope CurrentUser to download the module from the PowerShell Gallery. Note that the first time you install from the remote repository it may ask you to first trust the repository.

Option 2: Installer Script

  1. Download the master branch to your workstation.
  2. Open a Powershell console with the Run as Administrator option.
  3. Run Set-ExecutionPolicy using the parameter RemoteSigned or Bypass.
  4. Run the Install-Rubrik.ps1 script in the root of this repository and follow the prompts to install, upgrade, or delete your Rubrik Module contents.

Than lets see some commands:

 

These are the list of commands which you can execute from PowerShell.

Now lets start with how we connect :

So you get connected to the cluster. Once you are connected:

When we run this we see multiple instances loaded on the cluster .

Lets check the list of filesets now:

 

It gives you amazing set of information which you can customize accordingly as in how you need them in your environment.

You can use : Get-Command -Module Rubrik command to explore the list on Rubrik Module

Please comment on this article if you need any information regarding the powershell execution against Rubrik Module.

Boot Device for VSAN

tapasmahanta1241 Comment

Starting an ESXi installation that is a part of a vSAN cluster from a flash device imposes certain restrictions.

When you boot a vSAN host from a USB/SD device, you must use a high-quality USB or SD flash drive of 4 GB or larger.

When you boot a vSAN host from a SATADOM device, you must use single-level cell (SLC) device. The size of the boot device must be at least 16 GB.

During installation, the ESXi installer creates a coredump partition on the boot device. The default size of the coredump partition satisfies most installation requirements. (You need to configure the core dump partition)

  • If the memory of the ESXi host has 512 GB of memory or less, you can boot the host from a USB, SD, or SATADOM device.

  • If the memory of the ESXi host has more than 512 GB, consider the following guidelines.

    • You can boot the host from a SATADOM or disk device with a size of at least 16 GB. When you use a SATADOM device, use a single-level cell (SLC) device.

    • If you are using vSAN 6.5 or later, you must resize the coredump partition on ESXi hosts to boot from USB/SD devices. For more information, see the VMware knowledge base article at http://kb.vmware.com/kb/2147881.

Hosts that boot from a disk have a local VMFS. If you have a disk with VMFS that runs VMs, you must separate the disk for an ESXi boot that is not for vSAN. In this case you need separate controllers.

Best Practices VSAN Networking

tapasmahanta1241 Comment

Consider networking best practices for vSAN to improve performance and throughput.

  • For hybrid configurations, dedicate at least 1-GbE physical network adapter. Place vSAN traffic on a dedicated or shared 10-GbE physical adapter for best networking performance.

  • For all-flash configurations, use a dedicated or shared 10-GbE physical network adapter.

  • Provision one additional physical NIC as a failover NIC.

  • If you use a shared 10-GbE network adapter, place the vSAN traffic on a distributed switch and configure Network I/O Control to guarantee bandwidth to vSAN.

Monitor the Resynchronization Tasks in the vSAN Cluster

tapasmahanta1241 Comment

To evaluate the status of objects that are being resynchronized, you can monitor the resynchronization tasks that are currently in progress.

Prerequisites

Verify that hosts in your vSAN cluster are running ESXi 6.5 or later.

Procedure

  1. Navigate to the vSAN cluster in the vSphere Web Client.
  2. Select the Monitor tab and click vSAN.
  3. Select Resyncing Components to track the progress of resynchronization of virtual machine objects and the number of bytes that are remaining before the resynchronization is complete.

    NOTE: If your cluster has connectivity issues, the data on the Resyncing Components page might not get refreshed as expected and the fields might reflect inaccurate information.

Maintenance Mode on VSAN

tapasmahanta1241 Comment

Any maintenance activity on ESXi host running VSAN, the first thing you will want to do is to place the host into Maintenance Mode. If you have never performed this operation on a VSAN host before, you should be aware that there is a new option to specify how the data for VSAN will be migrated. Below is a screenshot of three options provided when using the vSphere Web Client.

Procedure:

  1. Right-click the host and select Maintenance Mode > Enter Maintenance Mode.
  2. Select a data evacuation mode and click OK.

Ensure data accessibility from other hosts:

++++++++++++++++++++++++++++++

This is the default option. When you power off or remove the host from the cluster, vSAN ensures that all accessible virtual machines on this host remain accessible. Select this option if you want to take the host out of the cluster temporarily, for example, to install upgrades, and plan to have the host back in the cluster. This option is not appropriate if you want to remove the host from the cluster permanently.

Evacuate all data to other hosts:

+++++++++++++++++++++++++

vSAN evacuates all data to other hosts in the cluster, maintains or fixes availability compliance for the affected components, and protects data when sufficient resources exist in the cluster. Select this option if you plan to migrate the host permanently. When evacuating data from the last host in the cluster, make sure that you migrate the virtual machines to another datastore and then place the host in maintenance mode.

This evacuation mode results in the largest amount of data transfer and consumes the most time and resources. All the components on the local storage of the selected host are migrated elsewhere in the cluster. When the host enters maintenance mode, all virtual machines have access to their storage components and are still compliant with their assigned storage policies.

No data evacuation:

+++++++++++++++++

vSAN does not evacuate any data from this host. If you power off or remove the host from the cluster, some virtual machines might become unaccessible.

How to move vSAN Datastore into a Folder?

tapasmahanta1241 Comment

vSphere Folders are commonly used by administrators for organizational purposes and/or permission delegation. When the customer tried to move their vSAN datastore into a folder using the vSphere Web Client (applies to HTML5 Web Client as well), what they found was that nothing happens even though the UI indicates the operation should be possible with the (+) symbol.

I decided to perform the operation using the vSphere API instead of the UI. Behind the scenes, the UI simply calls the MoveIntoFolder_Task() vSphere API which allows you to move various vSphere Inventory objects into a vSphere Folder.

For PowerCLI users, we can use Move-Datastore cmdlet which I will be using for this:

In my setup, I have one vSAN Datastores, one from a vSphere 6.0u3 environment . Lets say I want to move the 60u3 datastore to TEST. The following PowerCLI snippet below does exactly that:

Move-Datastore -Datastore (Get-Datastore "vsanDatastore") -Destination (Get-Folder "TEST")

You can see the TEST datastore .vSAN Datastores is now part of a vSphere Folder!

For now, if you need to move vSAN-based datastore into a vSphere Folder, simply use the vSphere API as a workaround.

Storage and Availability Technical Documents from Vmware

tapasmahanta1241 Comment

This was something I came across accidentally so thought it may be worth a very brief post about as I found some amazing contents there.

VMware Storage and Availability Technical Documents Hub 

This is an online repository of technical documents and “how to” guides including video documents for all storage and availability products within VMware. Namely, it has some very useful contents for 4 VMware product categories (as of now)

  • VSAN
  • SRM
  • Virtual Volumes
  • vSphere Replication

Let us check the VSAN section :

Than I just clicked on USE CASES:

What an amazing View of Use cases, this is what we need in our day in and out job.

Similarly there are some good technical documentation around vVols including overview, how to set up and implement VVols…etc.. However in comparison, the content is a little light for the others compared to VSAN, but I’m sure more content will be added as the portal gets developed further.

All the information are presented in HTML5 interface which is easy to navigate with handy option to print to PDF option on all pages if you wanna download the content as a PDF for offline reading which is great.

One amazing feature is at : vSAN Remote Office Deployment

Also : VMware vSAN Disaster Recovery