Secure your Azure deployment with Palo Alto VM-Series for Azure

When I talk to customers and colleagues about cloud offerings, most of them are still concerned about the cloud, and especially about the security of public cloud offerings. One of the most mentioned concerns is based on the belief, that each and every cloud-based VM is publicly reachable over the internet. This can be so, but it does not have to. It relies on your design. Maybe that is only a problem in germany. German privacy policies are the reason for the two german Azure datacenters. They are run by Deutsche Telekom, not by Microsoft. read more

vExpert 2017 – My 2 cents about the increasing number of vExperts

Last Wednesday, VMware has published a list with the vExperts for 2017.

I’m on this list. I’m on this list for the fourth time, which makes me very happy and proud. I was surprised that I’m on this list. I have written only a few blog posts last year. I sometimes tweet about VMware, and I am active in some forums. The focus of this blog has shifted. read more

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. read more

Single Sign On (SSO) with RemoteApps on Windows Server 2012 (R2)

A RemoteApp is an application, that is running on a Remote Desktop Session Host (RDSH), and only the display output is sent to the client. Because the application is running on a RDSH, you can easily deliver applications to end users. Another benefit is, that data is not leaving the datacenter. Software and data are kept inside the datacenter. RemoteApps can be used and deployed in various ways:

  • Users can start RemoteApps through the Remote Desktop Web Access
  • Users can start RemoteApps using a special RDP file
  • Users can simply start a link on the desktop or from the start menu (RemoteApps and Desktop connections deployed by an MSI or a GPO)
  • or they can click on a file that is associated with a RemoteApp

Even in times of VDI (LOL…), RemoteApps can be quite handy. You can deploy virtual desktops without any installed applications. Application can then delivered using RemoteAPps. This can be handy, if you migrate from RDSH/ Citrix published desktops to  VMware Horizon View. Or if you are already using RDSH, and you want to try VMware Horizon View. read more

Horizon View: Server certificate does not match the external url

Certificates are always fun… or should I say PITA?  Whatever… During a small Horizon View PoC, I noticed an error message for the View Connection Server.

That’s right, Mr. Connection Server. The certificate subject name does not match the servers external URL, as this screenshot clearly shows.

But both settings are unused, because a VMware Access Point appliance is in place. If I remove the certificate, that was issued from a public certificate authority, I get an error message because of an invalid, self signed certificate. read more

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

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

The Linux OOM killer strikes again

As a frequent reader of my blog, you might have noticed that 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 – read more

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

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