Author Archives: Patrick Terlisten

About Patrick Terlisten

vcloudnine.de is the personal blog of Patrick Terlisten. Patrick has nearly 2 decades of experience in IT, especially in the areas infrastructure, cloud, automation and industrialization. Patrick was selected as VMware vExpert (2014 - 2016), as well as PernixData PernixPro. Feel free to follow him on Twitter and/ or leave a comment.

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.

read more

Related Posts:

Using WP fail2ban with the CloudFlare API to protect your website

The downside of using WordPress is that many people use it. That makes WordPress a perfect target for attacks. I have some trouble with attacks, and one of the consequences is, that my web server crashes under load. The easiest way to solve this issue would be to ban those IP addresses. I use Fail2ban to protect some other services. So the idea of using Fail2ban to ban IP addresses, that are used for attacks, was obvious.

From the Fail2ban wiki:

Fail2ban scans log files (e.g. /var/log/apache/error_log) and bans IPs that show the malicious signs — too many password failures, seeking for exploits, etc. Generally Fail2Ban is then used to update firewall rules to reject the IP addresses for a specified amount of time, although any arbitrary other action (e.g. sending an email) could also be configured. Out of the box Fail2Ban comes with filters for various services (apache, courier, ssh, etc).

read more

Related Posts:

The Linux OOM killer strikes again

As a frequent reader of my blog, you might have noticed that vcloudnine.de was unavailable from time to time. Reason for this was, that my server was running out of memory at night.

Running out of memory is bad for system uptime. Sometimes you have to sacrifice someone to help others.

It is the job of the linux ‘oom killer’ to sacrifice one or more processes in order to free up memory for the system when all else fails.

Source: OOM Killer – linux-mm.org

read more

Related Posts:

2016 – How did it go?

The year 2016 is coming to an end (thank god…). 2016 was a difficult year. One of my goals for 2016 was to write more PowerShell code and to learn Python. I missed both goals. But hey, at least I cleaned up my Git account.I renewed my VCP by passing VCP6 in the first attempt, and I took the VCP7-DTM beta exam (no results yet). Since I am not the guy who attends conferences, I was not attending VMworld in Barcelona or HPE Discover in London. In fact: I was no at no conference or vendor roadshow, because I had an ass full of work.

read more

Related Posts:

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.

read more

Related Posts:

VMware EUC Access Point appliance – Name resolution not working after deployment

As part of a project, I had to deploy a VMware EUC Access Point appliance. Nothing fancy, because the awesome VMware Access Point Deployment Utility makes it easy to deploy.

Unfortunately, the deployed Access Point appliance was not working as expected. When I tried to access my Horizon View infrastructure behind the Access Point appliance, I got a HTTP 504 error. The REST API interface was working. I was able to exclude invalid certificates, routing, or firewall policies. I re-deployed the appliance using the the IP address of the connection server, instead of the FQDN. And this worked… I checked the name resolution with nslookup and the name resolution failed. So that was probably the problem.

read more

Related Posts:

Important foot note: Windows 10 Enterprise LTSB 2016 requires a new KMS host key

Today, I have stumbled upon a fact that is worth being documented.

TL;DR: Use the “Windows Srv 2016 DataCtr/Std KMS” host key (CSVLK), if you want to activate Windows 10 Enterprise LTSB 2016 using KMS. Or use AD-based activation. For more information read the blog post of the Ask the Core Team: Windows Server 2016 Volume Activation Tips.

A customer wants to deploy Windows 10 Enterprise LTSB 2016. A Windows Server 2012 R2 is acting as KMS host, and successfully activates Windows Server 2012 R2 and Microsoft Office 2013 Professional Plus. The “Windows Srv 2012R2 DataCtr/Std KMS for Windows 10” CSVLK was successfully installed. Nevertheless, the “current count” value does not increase. The client logged the event 12288:

read more

Related Posts:

Fight the chaos: Design your toolbox properly

You need tools and methods to accomplish your daily tasks. No one will deny this insight.

I would like to give you an insight into my box of tools and methods. These tools and methods work for me, but they do not have to work for you. The design of your personal toolbox depends on your job.

Depending on who you ask, my job role consists of several roles: Currently, I am working as a consultant, head of the business unit, pre-sales consultant and technical account manager. That’s what you get when working in a very small company… And because of these different roles, my personal toolbox may differ from yours.

read more

Related Posts:

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!

read more

Related Posts:

Enable IPv6 SLAAC on HPE OfficeConnect 1920 switches

The HPE OfficeConnect 1920 switch series is designed for SMBs. The switch is perfect for small environments, that require features like VLANs, routing or 802.1x. This switch is smart-managed, so it has “only” a web interface and only a limited CLI.

I have two switches in my lab: A 1910-8G and the successor, a 1920-24G. Although the device supports IPv6, it doesn’t support SLAAC (Stateless Address Autoconfiguration) by default. The switch does not send router advertisements (RA). I’m using IPv6 in my lab (Stateless DHCPv6 + SLAAC), so the missing RAs were a problem for me, or at least, annoying. Fortunately you can change the default behaviour.

read more

Related Posts: