August 6, 2018

Amazon VPC Basics

For the past five weeks we have been getting deep in our Scalable Solutions series.  At Entasis we work with our customers to help them build solutions that are Scalable in design, Resilient by nature, with Performance on demand.  We feel that these three components are the pillars that all truly scalable solutions are built with.  Here is what we have gone over thus far: […]
July 30, 2018

Amazon EC2 Security Groups

In this installment of our Scalable Solutions series we are going to be reviewing one of the core components of EC2, the security group.  We have found that our customers find that the elasticity provided by security groups allows them to build more resilient solutions and expand them as performance dictates it, with consistent security policies. In case you missed our previous articles you may […]
July 23, 2018

AWS Application Load Balancer

This week in our Scalable Solutions series we are going to be covering the Elastic Load Balancer (specifically the Application Load Balancer or v2). At Entasis we help our customers build elastic and resilient solutions with performance on-demand.  If you need help finalizing your design, or implementing your vision please don’t hesitate to reach out to us at sales@entasistech.com.  Also if you are just looking […]
July 16, 2018

AWS Systems Manager Parameter Store

At Entasis we help our customers understand and modify their technology stacks so that scaling is a function of cost not a function of technology.  However when we look at scaling one of the largest problems is the consistency of an environment.  When we are running 100 application nodes then the opportunity for one node to go sideways and start handling traffic differently is much […]
July 9, 2018

AWS Certificate Manager

Today we are going to take a look at another one of my favorite services.  AWS Certificate Manager.  In this exploration we are going to be interacting with JSON which Powershell makes more difficult then it ought to.  So please keep in mind that if you are using the AWS CLI on bash or cygwin or similar your mileage will vary (especially where it comes […]
July 2, 2018

Amazon Route 53 Basics

This post will kick off a series on Scalable Solutions.  Entasis uses a strong architectural emphasis in our AWS Solutions Group to deliver solutions that are Elastic by nature, Resilient in design, with Performance on demand.  These are the three pillars of Scalable Solutions.  In this series we will be going through some of the architectural components and decisions which allow us to design and […]
December 28, 2015

Linux: Replace Disk in MD

On my lab machines I use a pair of physical disks, configured in a RAID 1 with MD, with LVM on top of that.  This gives me a lot of flexibility with full redundancy.  However recently I had a failure of a drive. Identify the Failure Here is what MD was telling me after I identified and removed the drive from the chassis to send […]
September 16, 2015

Bash: Dynamic Volume Group Mounter

This is similar, but an enhanced version of my custom_mount.sh previously published here: Bash: Automatically Mount File Systems on Volume Group if Present. This previous version was just a simple init script.  This updated version is designed for newer Linux distributions that use Systemd instead of Init. The Code The majority of the work is done by dvgmounter.sh.  It will check if the Volume Group is […]
September 15, 2015

Fedora 20: Use PPTP VPN

I have had this one in the queue for a while (I don’t even run of Fedora 20 anymore).  This one will be short and sweet, because there really isn’t a bunch of discussion that needs to go into it. By default Fedora 20 will block outbound PPTP VPN connections. Reload the rules.
September 14, 2015

Zimbra 8.6: Bayesian Poisoning

Let me start by saying that this problem is not unique to Zimbra and it certainly isn’t unique the version 8.6, however I was using Zimbra 8.6 when I ran into this problem, so this is how I fixed it. What is Bayesian Poisoning? One of the core tenants of spam filtering using Bayesian probability to increase or decrease a particular messages score based on the […]
March 4, 2015

Fedora 20: Firefox Reports Flash as Vulnerable

This problem starts with Firefox reporting that your flash-plugin is out of date.  This report looks like this and disables all flash. After this we will take a look Mozilla’s Plugin Check to see what it thinks is going on. Now here we can see that version 11.2.202.440 is vulnerable.  We will then check about:plugins to see if it agrees. Again this is also reporting […]
February 26, 2015

BlackBerry Z30: No Update to 10.3.1

I have a BlackBerry Z30 (STA100-5) which I was excited to updated to the latest release of BB10, which was announced on February 9, 2015 (link).  However when I was attempting to install the update over the air, it kept telling me that I was already on the latest version.  This was obviously incorrect (I was on 10.2.1.3062 which is the latest prior to 10.3.1). […]
December 17, 2014

SPARC Logical Domains: Alternate Service Domains Part 3

In Part One of this series we went through the initial configuration of our Logical Domain hypervisor, and took some time to explain the process of mapping out the PCI Root Complexes, so that we would be able to effectively split them between the primary and an alternate domain. In Part Two of this series we took the  information from Part One and split out […]
December 16, 2014

SPARC Logical Domains: Alternate Service Domains Part 2

In Part One of this series we went through the initial configuration of our Logical Domain hypervisor, and took some time to explain the process of mapping out the PCI Root Complexes, so that we would be able to effectively split them between the primary and an alternate domain. In Part Two (this article) we are going to take that information and split out our […]
December 15, 2014

SPARC Logical Domains: Alternate Service Domains Part 1

In this series we will be going over configuring alternate I/O and Service domains, with the goal of increasing the serviceability the SPARC T-Series servers without impacting other domains on the hypervisor.  Essentially enabling rolling maintenance without having to rely on live migration or downtime.  It is important to note, that this is not a cure-all, for example base firmware updates would still be interruptive, […]
December 9, 2014

SPARC Logical Domains: Live Migration

One of the ways that we are able to accomplish regularly scheduled maintenance is by utilizing Live Migration, with this we can migrate workloads from one physical machine to another without having service interruption.  The way that it is done with Logical Domains is much more flexible than with most other hypervisor solutions, it doesn’t require any complicated cluster setup, no management layer, so you […]
December 8, 2014

Solaris 11: Configure IP Over Infiniband Devices

In this article we will be going over the configuration of an infiniband interface with the IPoIB protocol on Solaris 11, specifically Solaris 11.2 (previous versions of Solaris 11 should work the same, however there have been changes in the ipadm and dladm commands). Identify Infiniband Datalinks First we need to identify the underlying interfaces of the infiniband interfaces.  In my case net2 and net3. […]
December 1, 2014

Adventures in ZFS: Mirrored Rpool

It always makes sense to have a mirrored rpool for your production systems, however that is not always how they are configured.  This really simple procedure is also critical. Create a Mirrored Zpool Check the existing devices to identify the one currently in use. Once we know which one is currently in use, we need to find a different one to mirror onto. Then we […]
October 27, 2014

Linux KVM: Bridging a Bond on CentOS 6.5

Today we are going to hop back into the KVM fray, and take a  look at using CentOS as a hypervisor., and configuring very resilient network connections to support our guests.  Of course these instructions should be valid on Red Hat Linux and Oracle Linux as well, though there is a little more to be done around getting access to the repos on those distributions… […]
October 21, 2014

BlackBerry OS 10: Caldav Setup with Zimbra

I have owned my Blackberry Z10, going on a year now, and I have absolutely loved it.  However one of the issues that I have fought was in integrating it with my Zimbra Installation.  Email was easy, the IMAP protocol sorted that out easily enough…  However calendars turned out to be more of a challenge than I expected. Here is the versions that I validated […]
July 29, 2014

Voyage Linux: Dialog Error with Apt

This can happen on other Linux distributions, however in this case I found it on Voyage Linux, which is a Linux distribution for embedded hardware. The Error Here we are dealing with an annoyance whenever you use apt-get or aptitude. The Fix Simply install dialog, which is the package it is not finding.  This will no longer need the failback to readline. Once the dialog […]
July 28, 2014

Voyage Linux: Locale Error with Apt

Voyage Linux is an embedded linux distribution.  I use it on some ALIX boards I have lying around, it is very stripped down, and as such there are a few annoyances which we have to fix. The Error This issue happens when attempting to install/upgrade packages using apt-get or aptitude. The Fix We simply need to set the locales to use en_US.UTF-8 or whichever locale […]
July 9, 2014

Adventures in ZFS: Splitting a Zpool

Today we are going to go through the process of splitting a zpool.  This is not something that you will do often, but when you do it, you must be very precise and do it properly. Create Our Test Zpool First we will create a ZFS to hold our disk images. Next we will create the disk images. Finally we will create our zpool, which […]
July 8, 2014

SQL Developer Crash on Fedora 20

I ran into a painful issue on Fedora 20 with SQL Developer.  Basically every time it was launched via the shortcut it would go through loading, and then disappear. Manual Invocation of SQL Developer When launching it via the script itself it gives us a little more information. I also noticed, that while executing as root it worked.  However that clearly isn’t the “solution” Fixing […]

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