The ramblings of a computer geek
I was getting the following error with Ansible when running a Playbook against a server: It turned out that Ansible was attempting to perform an “apt update” and failing, but just ended up timing out. Manually running “apt update” then gave the following error, which was what was tripping up the Playbook and causing it … Read more
GNS3 can run on Windows, Linux or MacOS, however for large scale network simulations running it on a dedicated server machine (typically Linux) is recommended. The deployment of this can be difficult due to limited documentation, the following provides a guide for the installation of GNS3 on a dedicated Linux server, ideally with as much … Read more
Although the PowerShell ISE is now no longer supported (apparently), you can allow it to use PowerShell 7, which can be handy if you need to use some of the new PowerShell 7 commands, not available in PowerShell 5 or 6 for example. Or just use VS Code! Firstly ensure you have PowerShell 7 installed … Read more
Microsoft has announced that Office 365 (Exchange Online) now supports up to 150MB email messages, quite a large increase from the previous limit of 25MB. Within Exchange Online you don’t get the level of control you had on Microsoft Exchange on-premise servers, where you could configure the size limits on Organisation Wide transport configuration, Send/receive connectors, AD site links … Read more
Kubernetes is a container orchestration platform, it allows you to run many containerised workloads (applications) in a scalable, secure, reliable and adaptable way. It is however quite complex to build and manage. To explore a Kubernetes deployment we are going to be using Kubespray to deploy and manage a Kubernetes cluster which is built upon … Read more
The CPU Ready Time shows how much time the VM is waiting to use the CPU on the VMware Host. Obviously you want this figure to be as low as possible, but typically below 10% is fine. The more you oversubscribe a host, the higher the CPU Ready Time because the VM(s) spend more time … Read more
Let’s say you have your workstation with PuTTY installed, and you have accessed a remote machine via SSH. If you wanted to get to a service running on that remote machine you’d either need direct port access from your workstation to the remote machine on that port, or you can tunnel a port (or ports) … Read more
We had an issue with event ID 2004 being logged on our Exchange Servers, grumbling about a missing certificate. Warning Observed The following error is observed: Analysis It seems to indicate that an expected certificate is missing. Running the “get-authconfig” gives this output, and we can see that the PreviousCertificateThumbprint Confirm Current Certificate Confirm that … Read more
Although not good security practice, it can be helpful for a user to account to have at least some (or all) sudo ability without the need to re-enter the user’s password to gain sudoers. By adding the user within the file /etc/sudoers (via visudo is recommended for Ubuntu Linux), with the following, you can ensure … Read more
In part 4 of the series we are exploring Metrics. Although we’ll go into more detail later on in the series. Kubernetes can collect metrics of attributes like CPU or Memory etc. These metrics are collected by a Metrics Server, you can use the built in Kubernetes one (Metrics Server), or you can use external … Read more