Category: PowerShell

Step-by-Step – Installing System Center Operations Manager (SCOM) 2019 on Windows Server 2019 with SQL 2017

This post I will be installing System Center Operations Manager 2019 (SCOM) RTM, Build Number 10.19.10050.

Here is some of the background information. As this post will concentrate on the installation of SCOM 2019, I am going to omit the setup and configuration of the Domain Controller, Windows Server 2019 for the SCOM Management Server. Also to note, I am using a PaaS instance of SQL 2017 (hosted on Azure), likewise the entire environment lives on Azure in an IaaS and PaaS configuration.

Service Accounts and Local Administrator:

DomainAccount Description Local Admin on…
domainSCOM_AA SCOM Action Account SCOM
domainSCOM_DA SCOM Data Access/SDK Account SCOM
domainSCOM_SQL_READ SCOM SQL Reader n/a
domainSCOM_SQL_WRITE SCOM SQL Writer n/a
domainSCOM_Admins SCOM Administrators Group SCOM
domainSQL_SA SQL Service Account n/a

Now, if you’re lazy like me, or are tired of doing this setup for environments, I have scripted the automation of these accounts. You can find that link here, Microsoft TechNet Gallery.


Let’s Begin:

Since I am hosting SQL on a dedicated server, I will install SSRS (SCOM Reporting) on that server.

Well, that’s not new… Prerequisites. Since this is a clean, vanilla Windows 2019 server, we will need to install all the necessary Web Console components, along with Report Viewer Controls (probably SQL CLR Types too..).

  • For the Report Viewer Prerequisites, go HERE.
  • Here is the PowerShell command I ran to install the necessary IIS features/roles:
Import-Module ServerManager
Add-WindowsFeature Web-Server, Web-WebServer, Web-Common-Http, Web-Default-Doc, Web-Dir-Browsing, Web-Http-Errors, Web-Static-Content, Web-Health, Web-Http-Logging, Web-Log-Libraries, Web-Request-Monitor, Web-Performance, Web-Stat-Compression, Web-Security, Web-Filtering, Web-Windows-Auth, Web-App-Dev, Web-Net-Ext45, Web-Asp-Net45, Web-ISAPI-Ext, Web-ISAPI-Filter, Web-Mgmt-Tools, Web-Mgmt-Console, Web-Mgmt-Compat, Web-Metabase, NET-Framework-45-Features, NET-Framework-45-Core, NET-Framework-45-ASPNET, NET-WCF-Services45, NET-WCF-HTTP-Activation45, NET-WCF-TCP-PortSharing45, WAS, WAS-Process-Model, WAS-Config-APIs -restart

 

Once the server is back online, you will need to register ASP.Net.

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You will need to apply the following using Command Prompt (as Administrator)). Yes, this is a screenshot from a previous post…Forgot to capture the screenshot when running it this time..

  1. cd %WINDIR%Microsoft.NETFramework64v4.0.30319
  2. aspnet_regiis.exe -r
  3. IISRESET
  4. Reboot your server…

Once the server is back online, let’s try that Prerequisites check again….

Great! Now all of Prerequisites have been met!

Provide a meaningful Management Group Name (there’s no going back after this…)

SQL Server will be where your SCOM SQL instance(s) were installed. Remember, to either disable the Windows Firewall, or open SQL TCP Ports 1433.

 

I recommend always keeping this off, and manually updating your SCOM infrastructure.

One quick review. Looks good. Hit Install, and get some fresh air!

A few minutes later….

Sweet! All good. I hope this helps. If you have any questions or issues, please drop me a line.

Happy 2019 SCOM’ing!

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System Center Operations Manager (SCOM) 2019- Requirements for Windows Server 2019 via PowerShell

The following PowerShell code is to install all the necessary IIS components for System Center Operations Manager (SCOM) 2019 Web Console on Windows Server 2019.

Import-Module ServerManager
Add-WindowsFeature Web-Server, Web-WebServer, Web-Common-Http, Web-Default-Doc, Web-Dir-Browsing, Web-Http-Errors, Web-Static-Content, Web-Health, Web-Http-Logging, Web-Log-Libraries, Web-Request-Monitor, Web-Performance, Web-Stat-Compression, Web-Security, Web-Filtering, Web-Windows-Auth, Web-App-Dev, Web-Net-Ext45, Web-Asp-Net45, Web-ISAPI-Ext, Web-ISAPI-Filter, Web-Mgmt-Tools, Web-Mgmt-Console, Web-Mgmt-Compat, Web-Metabase, NET-Framework-45-Features, NET-Framework-45-Core, NET-Framework-45-ASPNET, NET-WCF-Services45, NET-WCF-HTTP-Activation45, NET-WCF-TCP-PortSharing45, WAS, WAS-Process-Model, WAS-Config-APIs, web-asp-net -restart

You can also find this in Microsoft’s TechNet Gallery, HERE.

Deploy an Azure Cloud Witness for your Failover Cluster Quorum for Windows Server 2016 & 2019 with PowerShell

For the longest time, when deploying a cluster with Windows Server, you only had the two options,

  1. Using a dedicated disk for the quorum, or
  2. Configuring an SMB file-share as the quorum witness

With Server 2016 and 2019, there is now a third option, Cloud Witness. The Cloud Witness leverages Azure Blob storage to provide that additional cluster/quorum vote.

Before showing you how this is done, one should understand the purpose of a witness/quorum is with respect to a failover cluster.

When one or more members of a cluster stops reporting to the other cluster members, there is a vote. The vote ensures that there is no split-vote, and ensures the cluster has a true owner. For example, in a two node cluster, if each node believe it is the owner, then this will cause a “split-brain”. In short, neither node will ever agree it is the owner (or not). This is where a quorum is required to determine who is the owner by providing the third vote, ie. majority. This ensures the cluster has a true owner by having the majority of votes. Each member gets a vote, plus the quorum.

Why this matters, in the even there is no quorum, a node from the cluster can be evicted and as a result will suspend all application services to prevent data corruption by more than one system writing data without the cluster services coordinating data writes and access. Depending on policies, VMs running on the ejected cluster member will either suspend operations or be migrated to other nodes before being ejected.

Below is a step-by-step guide on how to configure the Azure Blob storage as the Cloud Witness.

Assumptions:

  • The Azure Blob storage account has already been created,
  • The cluster with at least 2 nodes already exists.

Launch the PowerShell console as Administrator, and execute the following cmdlet:

Set-ClusterQuorum -CloudWitness -AccountName "storage_account_name" -AccessKey "primary_access_key"

Now if we go back to the Failover Manager console we can see we have successfully configured cluster with a Cloud Witness.

In conclusion, deploying a Cloud Witness for a Failover Cluster is very simple, and in case of power outage in one datacenter, maintenance on a node, etc. then the entire cluster and its members (nodes) are all given an equal opportunity. Not only is it recommended and a requirement for 2-node clusters, but for any number of nodes, having a quorum is key ensuring high-availability.  As mentioned, there are the traditional options such as using a dedicated disk or a file-share (SMB) as the cluster witness. However with Azure Blob storage with its 16×9 uptime, we can always ensure the quorum witness is online and available.

DNS commands (Command Prompt vs PowerShell)

Recently I discovered Windows PowerShell has the ability to clear the local DNS on a machine, just like the traditional Command Prompt. Below is a table of the most common commands I personally use on a day-to-day basis and its PowerShell equivalent(s). Of course there are more PowerShell cmdlets, see the URL below for the complete list.

Command Prompt PowerShell Description
ipconfig /flushdns Clear-DnsClientCache Clears the contents of the DNS client cache.
ipconfig /registerdns Register-DnsClient Registers all of the IP addresses on the computer onto the configured DNS server.
ipconfig /displaydns Get-DnsClientCache Retrieves the contents of the DNS client cache.
 

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Flush DNS Cache with PowerShell

For years I have always been using Windows’s command prompt to flush the DNS cache on a local machine. As we know, that command is pretty well known, “ipconfig /flushdns“. Turns out there is an equivalent command we can run within the PowerShell console, and that is, “Clear-DnsClientCache“. Clear-DnsClientCache does exactly what it states, it clears the contents of the DNS client cache/local machine. Consider this next time you need to flush the local machine’s DNS cache.

Clear-DnsClientCache

Enabling SCOM 2016 Agent Proxy

Not too much has changed when it comes to SCOM 2012R2 and SCOM 2016. This post is a similar post to SCOM 2012R2, but applicable to SCOM 2016. (See that post here).

You could go to the computer that SCOM is complaining about and manually enable the agent proxy via Administration > Managed Computers, and modifying its properties, see below:

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Or…… you could make your life easier, and do this…

The fix is easy, and the explanation are both below:

To resolve the “Agent proxy not enabled” alert for all machines in your current environment, run the following PowerShell code in the SCOM PowerShell Console:

get-SCOMagent | where {$_.ProxyingEnabled -match "False"} | Enable-SCOMAgentProxy

To prevent this alert in the future, run the following below:

add-pssnapin "Microsoft.EnterpriseManagement.OperationsManager.Client"; new-managementGroupConnection -ConnectionString:<strong>yourSCOMMGMTserverFQDNhere</strong>; set-location "OperationsManagerMonitoring::"; Set-DefaultSetting -Name HealthService\ProxyingEnabled -Value True

 

How To Disable Azure AD Connect via PowerShell

Recently I came across an environment where Exchange was being migrated to Office 365. As you may know, DirSync is no longer supported for Exchange/O365 migrations and Microsoft recommends you now use Azure AD Connect.

With that said, recently in a PoC environment, using Azure AD Connect, the domain controller that was running the Azure AD Connect utility was never uninstalled, and the VM was shortly deleted. Well, as a result, the O365 admins are now getting reminded daily that their AD Sync has failed to connect.

As of today, there is no way to disable Azure AD Connect via the Azure Resource Manager (ARM) portal, but this can be done with some PowerShell. If you take a look at the ARM portal, there is no option to currently disable the directory synchronization.

First, you will need to install the Azure Active Directory Connection utility, the download for that can be found HERE. This will provide you the PowerShell cmdlet’s needed to run the code below. No, AzureADPreview V2 will not work (yet…).

Once installed, launch the PowerShell console and we will need to connect to Azure AD and trigger the Directory Sync to false. Below are the commands you will need to get this done. Note, you will need an Azure global admin account with the *@*.onmicrosoft.com domain to successfully sign into Azure AD via PowerShell.

#specify credentials for azure ad connect
$Msolcred = Get-credential
#connect to azure ad
Connect-MsolService -Credential $MsolCred
#disable AD Connect / Dir Sync
Set-MsolDirSyncEnabled –EnableDirSync $false 
#confirm AD Connect / Dir Sync disabled
(Get-MSOLCompanyInformation).DirectorySynchronizationEnabled 

If you choose to re-enable the AD Connect, just change the flag to TRUE.

Set-MsolDirSyncEnabled –EnableDirSync $true 

Once complete, we can now verify the Directory Sync has now been disabled in ARM.

For more on Azure AD PowerShell cmdlets, visit the following page, HERE.