Tag Archives: powershell

Azure PowerShell vs. Azure RM PowerShell

In 2014, Microsoft announced the Azure Preview Portal, which was going GA in December 2015. Since January 8, 2018, the classic Azure Portal is turned off. The “Preview Portal” was more than a facelift. The classic Azure Portal was based on the Service Management mode, often called the “classic deployment model”, whereas the new Azure Portal uses the Resource Manager model. Azure Service Management (ASM) and Azure Resource Management are both deployment models. The Resource Manager model eases the deployment of complex setups by using templates to deploy, update and manage resources within a resource group as a single operation.

Azure PowerShell vs. Azure RM PowerShell

Different deployment models require different tools. Because of this, Microsoft offers two PowerShell modules for Azure. Depending on your deployment type, you have to use the Azure or AzureRM module. Both can be installed directly from the PowerShell Gallery using Install-Module -Name Azure or Install-Module -Name AzureRM .

Connect to Azure

Depending on the used module, the ways to connect to Azure differ.

Module AzureRM

You will notice, that AzureRM sessions does not persist between PowerShell sessions. This behaviour differs from Add-AzureAccount . But you can save and load your AzureRM session once you are connected.

Module Azure

How to install PowerShell Core on Linux Mint 18

Beside my Lenovo X250, which is my primary working machine, I’m using a HP ProBook 6450b. This was my primary working machine from 2010 until 2013. With a 128 GB SSD, 8 GB RAM and the Intel i5 M 450 CPU, it is still a pretty usable machine. I used it mainly during projects, when I needed a second laptop (or the PC Express card with the serial port…). It was running Windows 10, until I decided to try Linux MInt. I used Linux as my primary desktop OS more than a decade ago. It was quite productive, but especially with laptops, there were many things that does not worked out of the box.

Because I use PowerShell quite often, and PowerShell is available for Windows, MacOS and Linux, the installation of PowerShell on this Linux laptop is a must.

How to install PowerShell?

Linux Mint is a based on Ubuntu, and I’m currently using Linux Mint 18.2. Microsoft offers different pre-compiled packages on the PowerShell GitHub repo. For Linux Mint 18, you have to download the Ubuntu 16.04 package. For Linux Mint 17, you will need the 14.04 package. Because you need the shell to install the packages, you can download the deb package from the shell as well. I used wget to download the deb package.

The next step is to install the deb package, and to fix broken dependencies. Make sure that you run dpkg  with sudo .

Looks like it failed, because of broken dependencies. But this can be easily fixed. To fix the broken dependencies, run apt-get -f install . Make sure that you run it with sudo !

That’s it! PowerShell is now installed.

Yep, looks like a PowerShell prompt…on Linux. Thank you, Microsoft! :)

Wrong iovDisableIR setting on ProLiant Gen8 might cause a PSOD

TL;DR: There’s a script at the bottom of the page that fixes the issue.

Some days ago, this HPE customer advisory caught my attention:

Advisory: (Revision) VMware – HPE ProLiant Gen8 Servers running VMware ESXi 5.5 Patch 10, VMware ESXi 6.0 Patch 4, Or VMware ESXi 6.5 May Experience Purple Screen Of Death (PSOD): LINT1 Motherboard Interrupt

And there is also a corrosponding VMware KB article:

ESXi host fails with intermittent NMI PSOD on HP ProLiant Gen8 servers

It isn’t clear WHY this setting was changed, but in VMware ESXi 5.5 patch 10, 6.0  patch 4, 6.0 U3 and, 6.5 the Intel IOMMU’s interrupt remapper functionality was disabled. So if you are running these ESXi versions on a HPE ProLiant Gen8, you might want to check if you are affected.

To make it clear again, only HPE ProLiant Gen8 models are affected. No newer (Gen9) or older (G6, G7) models.

Currently there is no resolution, only a workaround. The iovDisableIR setting must set to FALSE. If it’s set to TRUE, the Intel IOMMU’s interrupt remapper functionality is disabled.

To check this setting, you have to SSH to each host, and use esxcli  to check the current setting:

I have written a small PowerCLI script that uses the Get-EsxCli cmdlet to check all hosts in a cluster. The script only checks the setting, it doesn’t change the iovDisableIR setting.

Here’s another script, that analyzes and fixes the issue.

Creating console screenshots with Get-ScreenshotFromVM.ps1

Today, I had a very interesting discussion. As part of an ongoing troubleshooting process, console screenshots of virtual machines should be created.

The colleagues, who were working on the problem, already found a PowerCLI script that was able to create screenshots using the Managed Object Reference (MoRef). But unfortunately all they got were black screens and/ or login prompts. Latter were the reason why they were unable to run the script unattended. They used the Get-VMScreenshot script, which was written by Martin Pugh.

I had some time to take a look at his script and I created my own script, which is based on his idea and some parts of his code.

This file is also available on GitHub.

One important note: If you want to take console screenshots of VMs, please make sure that display power saving settings are disabled! Windows VMs are showing a black screen after some minutes. Please disable this using the energy options, or better using a GPO. Otherwise you will capture a black screen!

Checking the 3PAR Quorum Witness appliance

Two 3PAR StoreServs running in a Peer Persistence setup lost the connection to the Quorum Witness appliance. The appliance is an important part of a 3PAR Peer Persistence setup, because it acts as a tie-breaker in a split-brain scenario.

While analyzing this issue, I saw this message in the 3PAR Management Console:

In addition to that, the customer got e-mails that the 3PAR StoreServ arrays lost the connection to the Quorum Witness appliance. In my case, the CouchDB process died. A restart of the appliance brought it back online.

How to check the Quorum Witness appliance?

You can check the status of the appliance with a simple web request. The documentation shows a simple test based on curl. You can run this direct from the BASH of the appliance.

But you can also use the PowerShell cmdlet Invoke-WebRequest.

If you add /witness to the URL, you can test the access to the database, which is used for Peer Persistence.

If you get a connection error, check if the beam process is running.

If not, reboot the appliance. This can be done without downtime. The appliance comes only into play, if a failover occurs.

Tiny PowerShell/ Azure project: Deploy-AzureLab.ps1

One of my personal predictions for 2017 is, that Microsoft Azure will gain more market share. Especially here in Germany. Because of this, I have started to refresh my knowledge about Azure. A nice side effect is that I can also improve my PowerShell skills.

Currently, the script creates a couple of VMs and resource groups. Nothing more, nothing less. The next features I want to add are:

  • add additional disks to the DCs (for SYSVOL and NTDS)
  • promote both two servers to domain controllers
  • change the DNS settings for the Azure vNetwork
  • deploy a Windows 10 client VM

I created a new repository on GitHub and shared a first v0.1 as public Gist. Please note, that this is REALLY a v0.1.

Surprise, surprise: Enable/ disable circular logging without downtime

As part of a troubleshooting process, I had to disable circular logging on a Microsoft Exchange 2013 mailbox database, that was part of a Database Availability Group (DAG).

What is circular logging? Microsoft Exchange uses log files that record all transactions and modifications to a mailbox database. In this case, Exchange works like MS SQL or Oracle. These log files are used, to bring the database back to a consistent state after a crash, or to recover a database to a specific point-in-time. Because everything is written to log files, the number of log files increases over time. Log files are truncated, as soon as a successful full backup of the database is taken.

If you don’t need the capability to recover to a specific point-in-time, or if you are running low on disk space, circular logging can be an alternative. Especially if you are running low on disk space, because your backup isn’t working as expected. With circular logging enabled, Microsoft Exchange maintains only the minimum number of log files that is necessary, to keep the Exchange server running. As soon as a transaction was written to the database, the log file will be overwritten.

I rarely use circular logging. But this time I had to. As already mentioned, I had a mailbox database with enabled circular logging. This database was part of a DAG and I had to disable circular logging. Usually, you need to dismount and re-mount the database after enabling or disabling circular logging.

You can enable or disable circular logging using the Microsoft Exchange Control Panel (ECP), or with the Microsoft Exchange Management Shell. I have used the PowerShell.

To my surprise, dismounting and re-mounting the database was not necessary. The circular logging was disabled without downtime. I’ve checked the TechNet, and the observed behaviour was confirmed.

JET vs. CRCL

A non-replicated mailbox databases will use JET circular logging. If the database is part of a DAG, the database will use continuous replication circular logging (CRCL). A benefit of CRCL is, that it can be enabled and disabled without the need of dismounting and re-mounting the mailbox database.

To get this clear: This only works if you are using replicated mailbox databases, because only databases that belong to a DAG are using CRCL. If you are using standalone mailbox databases, you have to dismount and re-mount the database, after enabling or disabling circular logging.

As I mentioned earlier: I really don’t use circular logging often, but that was very handy today!

HPE ProLiant PowerShell SDK

Some days ago, my colleague Claudia and I started to work on a new project: A greenfield deployment consisting of some well known building blocks: HPE ProLiant, HPE MSA, HPE Networking (now Aruba) and VMware vSphere. Nothing new for us, because we did this a couple times together. But this led us to the idea, to automate some tasks. Especially the configuration of the HPE ProLiants: Changing BIOS settings and configuring the iLO.

Do not automate what you have not fully understood

Some of the wisest words I have ever said to a customer. Modifying the BIOS and iLO settings is a well understood task. But if you have to deploy a bunch of ProLiants, this is a monotonous, and therefore error prone process. Perfect for automation!

Scripting Tools for Windows PowerShell

To support the automation of HPE ProLiant deployments, HPE offers the Scripting Tools for Windows PowerShell. HPE offers the PowerShell modules free for charge. There are three different downloads:

  • iLO cmdlets
  • BIOS cmdlets
  • Onboard Administrator (OA) cmdlets

The iLO cmdlets include PowerShell cmdlets to configure and manage iLO on HPE ProLiant G7, Gen8 or Gen9 servers. The BIOS cmdlets does not support G7 servers, so you can only configure and manage legacy and UEFI BIOS for Gen8 (except DL580) and all Gen9 models. The OA cmdlets support the configuration and management of the HPE Onboard Administrator, which is used with HPEs well known ProLiant BL blade servers. The OA cmdlets need at least  OA v3.11, whereby v4.60 is the latest version available.  All you need to get started are

  • Microsoft .NET Framework 4.5, and
  • Windows Management Framework 3.0 or later

If you are using Windows 8 or 10, you already have PowerShell 4 respectively PowerShell 5.

Support for HPE ProLiant Gen9 iLO RESTful API

If you have ever seen a HPE ProLiant Gen9 booting up, you might have noticed the iLO RESTful API icon down right. Depending on the server model, the BIOS cmdlets utilize the ILO4 RESTful API. But the iLO RESTful API ecosystem is it worth to be presented in an own blog post. Stay tuned.

Documentation and examples

HPE offers a simple documentation for the BIOS, iLO and OA cmdlets. You can find the documentation in HPEs Information Library. Documentation is important, but sometimes example code is necessary to quickly ramp up code. Check HPEs PowerShell SDK GitHub repository for examples.

Time to code

I’m keen on it and curious to automate some of my regular deployment tasks with these PowerShell modules. Some of these tasks are always the same:

  • change the power management and other BIOS settings
  • change the network settings of the iLO
  • change the initial password of the iLO administrator account and create additional iLO user accounts

Further automation tasks are not necessarily related to the HPE ProLiant PowerShell SDK, but to PowerShell, respectively VMware PowerCLI. PowerShell is great to automate the different aspects and modules of an infrastructure deployment. You can use it to build your own tool box.

Get-MailboxDatabase doesn’t show last backup timestamp

Sometimes you have to check when the last backup of an Exchange mailbox database was taken. This is pretty simple, because the timestamps of the last full, incremental and differential backup is stored for each mailbox database. You can check these attributes using the Exchange Control Panel (ECP), or you can use the Get-MailboxDatabase cmdlet.

Backup successful, but no timestamp?

Take a look at this output. As you can see, there’s no timestamp for the last full, incremental and differential backup. But this database was successfully backuped some minutes before.

Missing -status switch

The solution is easy: The -status  switch was missing.

After adding the -status  switch to the Get-MailboxDatabase command, the timestamps were added to the output. If you run the command during a running backup session, this is also added to the output (BackupInProgress).

Exchange Management Shell (EMS) and new PowerShell releases

Some day ago, I installed a new Exchange 2013 CU11 for some test ins my lab. Nothing fancy, just a single server deployment on a Windows Server 2012 R2 VM. I deployed this Windows Server from a template, which was updated with the latest Windows Patches and WMF some days ago. The Exchange setup went smooth. I updated the SSL certificates and the internal and external URLs for the virtual directories. Then I started the Exchange Management Shell (EMS), to update the Autodiscover URL in the service connection point (SCP) of the Active Directory.

Well… that doesn’t look successful. I quickly switched to a PowerShell windows and imported the Exchange snap-in manually.

Looks better, isn’t it?

I compared my lab setup to a running Exchange 2013 single server deployment and I stumbled over the PowerShell version. In addition, I found the Windows Management Framework 5 Production Preview (KB3066437) on my freshly deployed Windows Server 2012 R2 VM.

After checking the Exchange Server Supportability Matrix, it was clear what had happened: WMF 5 is not supported (Source). Not supported with Exchange 2013, and also not supported with Exchange 2016.

exchange_supported_wmf

After I had removed KB3066437 from my Exchange server, the EMS loaded successfully.

You should ALWAYS check if installed applications are supported with newer version of PowerShell/ WMF! Currentyl, no Exchange version is supported with PowerShell 5/ WMF 5.