Articles tagged "Technical"

Planning to upgrade your Greenhost VPS? Great! Keeping a VPS's operating system up to date is important to make sure it keeps running smoothly and safely. OS updates bring new features, as well as security improvements, bug fixes, and resource-saving optimisations.

The latest versions of Debian and Ubuntu made a significant change in how some system files are stored. In some situations, you will need to do a quick and simple intervention before upgrading to Debian 12 Bookworm, releasing today (June 6th, 2023), or Ubuntu 22.04 Jammy Jellyfish, as the upgrade will not work out of the box on a...

Incident summary

During routine maintenance, the movement of a network cable brought to light a dormant issue in one networking component, resulting in a degraded connection. Later, while trying to fix this issue, an unrelated network cable was accidentally disconnected for a few seconds. As our infrastructure is built redundantly, both incidents should have had no impact. However, a software malfunction prevented another connection to take over on both system. This put them into an unstable state that resulted in a partial unavailability of our services between 15:20 and 19:45 CEST.

Resolution...

It is now possible to use cloud-init with our VPS's. Cloud-init scripts define what needs to be done immediately after a VPS is started for the first time. These files can be used to automate the setup of a VPS. This can range from small tasks — like configuring the machine or adding more users — to more complex tasks like installing software.

Cloud-init is a technology that is supported by many cloud providers. In addition to cloud-init scripts that you might find anywhere on the internet, Greenhost offers a repository with scripts that you can use to automate certain steps in setting up...

What follows is a relatively detailed and technical description of the reasons for the outage. Because we understand not everyone wants or understands this much detail we added a simpler and shorter summary of the problem:

There was a problem with the devices (switches) that regulate the (redundant) internet (network) connections to our data centre. In trying to solve this isolated problem unfortunately a feedback loop occurred that clogged the multiple connections.

We have multiple connections going to the data centre to prevent losing access to our machines, however this issue managed to...

As you may have read or heard, the Register announced several severe security problems with Intel processors, which are affecting nearly all computers with modern Intel processors (link below). This means an emergency maintenance window is scheduled from tomorrow onwards (January 4th), which can lead to downtime for your website or Virtual Private Server(s) outside the normal maintenance window. Please see below for more details.

Everyone has had the experience, staring at a browser and wondering why a particular website was taking such a long time to load. What makes websites slow can depend on several factors. Is the code efficient? Is the webserver efficient? How efficient is the storage? As a hosting provider mindful of sustainability, we are always trying to improve performance on our side, while also keeping redundancy in place as much as possible. Recently, we noticed one of our SQL servers was getting slower over time for no apparent reason, so we dug a little deeper to see how we could improve its performance.

We are proud to present our improved and more sustainable storage platform made with SSD drives and Ceph. As of today hosting at Greenhost will be faster, more resilient and scalable without downtime. It is the best new digital home for your websites, apps and projects.

Building a router with Linux is a viable alternative to commercial products in many applications. In this article, we explore the process of optimising Linux for the best packet-forwarding performance by exploiting symmetric multiprocessing (SMP) and Ethernet interfaces with multiple queues. We take advantage of the Linux kernel features known as Receive Packet Steering (RPS), Transmit Packet Steering (XPS), and IRQ affinity.