SHIFT-WIKI - Sjoerd Hooft's InFormation Technology
This WIKI is my personal documentation blog. Please enjoy it and feel free to reach out through blue sky if you have a question, remark, improvement or observation. See below for the latest additions, or use the search or tags to browse for content.
Allowed Downtime - Up to Five 9s
Summary: What would be your uptime - or downtime - for how many 9s.
Date: 20 February 2025
| Required Availability | Required Uptime hours/year | Allowable Downtime /year |
|---|---|---|
| 90% (0.9) | 7889.4 | 36.525 days |
| 99% (0.99) | 8678.34 | 3.6525 days |
| 99.9% (0.999) | 8757.23 | 8.766 hours |
| 99.99% (0.9999) | 8765.12 | 52.596 minutes |
| 99.999% (0.99999) | 8765.91 | 5.2596 minutes |
SRM: Add Hardware To Your DR Network
Summary: How to add a computer to your Disaster Recovery Network after a SRM failover test.
Date: Around 2017
Refactor: 20 February 2025: Checked links and formatting.
In case you do a test you might need some workstations in your testnetwork. This is how you do that, and note that all files should be located on the vCenter on your recoverysite. In this howto the scripts are located on the G-Drive.
The goal is simple, depending on if you're doing a test or a recovery, only one PC of a complete testroom should be added to the correct network. In this example we use these VLANs:
- Production network: 1
- Test network: 112
- Recovery network: 911
Upgrading AKS using Terraform
Summary: In this post I'll show you how to upgrade your AKS cluster using Terraform.
Date: 23 February 2025
Before we can start doing an upgrade, it's always good to gather some information about the current state of the cluster, as well as information about the new version and possible problems we might run into. Let's start with some links to the release notes and such and then continue with some commands to gather information.
It is also important to know, that when following this post, we will upgrade the following components in this order:
- Backplanes
- System nodepool
- User nodepool
AIX VIOS
Summary: ALthough AIX is by now on version 7.3 I find these old pages so fascinating I decided to keep them. On this page I'll show you how to install a VIOS server on a blade and what post-installation steps should or could be taken. This page is for AIX 5.3 and AIX 6.1.
Date: Between 2010-2013
Refactor: 21 December 2024: Checked formatting.