Failover Cluster Warning: The computer object associated with cluster network name resource could not be updated.

Cause

When you create a Windows Server failover cluster, a Cluster Computer object for the cluster name is created in Active Directory Domain Services (AD DS). The object is called a Cluster Name Object (CNO).

A new feature in Windows Server 2012 flags Cluster Computer objects to prevent them being deleted accidentally. If you do not have sufficient rights to the organizational unit (OU) in AD DS where the Computer objects are being created, an event is logged that notifies you that the cluster objects are not protected from accidental deletion.

Resolution

To resolve this issue, follow these steps:
Start Active Directory Administrative Center, and then select the tree view.
Select the CNO's organizational unit (OU).
Locate and right-click the CNO, and then click Properties.
Click to select the Protect from accidental deletion check box, and then click OK.
Note Cluster Computer objects that are not protected from accidental deletion have no adverse effect on the functionality of the cluster. If you are not concerned about the unintentional deletion of Cluster Computer objects, you can safely ignore this warning.

How to fix Hyper-V cannot be installed a hypervisor is already running

Enable-WindowsOptionalFeature –Online -FeatureName Microsoft-Hyper-V –All -NoRestart

The above command installs only the hypervisor but does not install the administration tools, if you want to manage the Hyper-V within the virtual machine you must install RSAT for Hyper-V to do this run the following command:

Install-WindowsFeature RSAT-Hyper-V-Tools -IncludeAllSubFeature

you want to create a cluster then you need to install the Cluster service, run: 
Install-WindowsFeature RSAT-Clustering -IncludeAllSubFeature 

you can install Multipath I/O to enable multiple paths to the storage, if this is your case follow:
Install-WindowsFeature Multipath-IO 


Restart to finalize the virtual machine with the command:
Restart-Computer

Microsoft Clustering on vSphere – Incompatible Device Errors for RDM attached VMs

When setting up a Microsoft Cluster with nodes running in vSphere Virtual Machines across ESXi hosts, I have come across folks who have experienced Incompatible device backing specified for device ‘0’ errors. These are typically a result of the RDM (Raw Device Mapping) setup not being quite right. There can be a couple of reasons for this, as highlighted here.

Different SCSI Controller

On one occasion, the RDM was mapped to the same SCSI controller as the Guest OS boot disk. Once the RDM was moved to its own unique SCSI controller, it resolved the issue. Basically, if the OS disk is configured to use SCSI 0:0, then you cannot put the RDM on SCSI 0:1, or SCSI 0:2. You must put the RDM on SCSI 1:x or SCSI 2:x.

Matching LUN ID

Another reason for the above error is when the RDM is presented to the different ESXi hosts using a different LUN ID. The RDM must be presented to all ESXi hosts (and thus all MSCS nodes) using the same LUN ID.

How to determine MS SQL Server memory allocation?

Run following query to find out MS SQL Server memory allocation.

SELECT  
(physical_memory_in_use_kb/1024) AS Memory_usedby_Sqlserver_MB,  
(locked_page_allocations_kb/1024) AS Locked_pages_used_Sqlserver_MB,  
(total_virtual_address_space_kb/1024) AS Total_VAS_in_MB,  
process_physical_memory_low,  
process_virtual_memory_low  
FROM sys.dm_os_process_memory;  

How much memory is used by each database in SQL Server?

 A large percentage of the memory of SQL Server instance is consumed by buffer pool. You can find out which databases are consuming more memory on SQL Server instance using below query.

SELECT
    CASE WHEN database_id = 32767 THEN 'Resource DB' ELSE DB_NAME (database_id) END AS 'DBName',
    COUNT (1) AS 'Page Count',
    (COUNT (1) * 8)/1024 AS 'Memory Used in MB' ,   
   CASE WHEN is_modified = 1 THEN 'Dirty Page' ELSE 'Clean Page' END AS 'Page State'
FROM sys.dm_os_buffer_descriptors
   GROUP BY [database_id], [is_modified]
   ORDER BY   db_name(database_id)
GO

How to create custom ESXi images using vSphere Image Builder?

Prerequisites : vSphere Power CLI, ESXi Offline Bundle

Image Builder is a set of PowerCLI Cmdlets that lets you build and maintain custom ESXi Images. Using the Image Builder you can;

Create/Edit an Image Profile
Clone an existing image
Add/Remove custom drivers

In this article shows how to clone existing image and add a custom driver to it and export as an iso image or offline bundle for vSphere Auto Deploy.

Add ESXi Offline Bundle to ESX software depot using Add-EsxSoftwareDepot command as shown below.

Check default ESXi images profiles for clone using the Get-EsxImageProfile command as shown bellow.

Choose desired ESXi image profile and clone it for changes as shown bellow.

Now you have completed the cloning image profile. It's time add a software package to cloned image. In my case, I'm going to add QLogic Fibre Channel Adapter driver.

Add QLogic Fibre Channel Adapter to ESX software depot using Add-EsxSoftwareDepot command as shown below.

Check added driver is on the VMware prepackaged-list using the Get-EsxSoftwarePackage command. For the QLogic Fibre Adapter driver, you can see “scsi-bfa” as shown bellow.

Use bellow command to confirm current software packages in the cloned image profile before.
Get-EsxImageProfile | select esxi55-custom-image -ExpandProperty VIBLIST
It will show you above “scsi-bfa” software driver has not added in the cloned image profile yet.

Use bellow command to add software driver to custom cloned image as shown bellow.

Once added use bellow command to verify it is added to the VIB list in the cloned image.
Get-EsxImageProfile | select esxi55-custom-image -ExpandProperty VIBLIST

Now the custom image is ready to export as ISO or as an Offline Bundle and use bellow commands.

Exported images as bellow.

You can verify the added software package with extracting the exported zip file under “vib20” folder for the software driver.