Basic information about images

CSC provides a set of standard images that are well suited for cloud use. In most cases you can use these images instead of creating your own. These images are created automatically using a tool called diskimage-builder. If you are interested in the details about how these images are created, see this GitHub page. These images are updated at regular intervals so that they contain the latest security updates at the time virtual machines are launched.

It is possible that for some use cases the automatically created images are not suitable. In this case it is possible to create your own images and use them instead. However, there are some caveats that you need to consider when creating your own images that you would not need to consider when using the default images. For more information you can look in our advanced images page

/ openstack image list --public /

What is the main differences between the images that CSC provides?

The images provided by CSC are mostly the same as upstream.



CentOS is the community version of Red Hat Enterprise Linux (RHEL). CentOS-7 is the distribution that the Pouta admins are most accustomed to, at least when it comes to work. This is the second newest major release of CentOS. At the time of writing we are still waiting for CentOS-8 cloud images to be released before we start providing CentOS-8 as well.


This is the oldest version of CentOS that we provide in Pouta. You should probably not use this version if you don't have a really good reason why. We will remove our pre-made CentOS-6 images once CentOS-6 is at end of life November 2020.


This is the same as CentOS-7 but it comes with pre-installed NVIDIA drivers. These are useful in combination with the GPU-flavors since you don't need to download the drivers yourself. We try to always have the latest NVIDIA drivers installed, but sometimes we are lagging a bit behind. These images are quite huge, so you should use the normal CentOS-7 image if you are not using a GPU-flavor VM.

ScientificLinux-7 and ScientificLinux-6

These are basically CentOS-7/CentOS-6 but with a bit different topping. Some research organizations are using ScientificLinux. If you are unsure you should prefer CentOS-7.

Ubuntu-18.04 LTS

Some like chocolate, some like strawberry. This is the choice for those that don't want to use CentOS. Note that Ubuntu-18.04 is that one image that has ubuntu as default username instance of cloud-user, since it was the first image type we started to provide directly from upstream.

Ubuntu-16.04 LTS

If you for some reason need an older version of Ubuntu.


Similar to CentOS-7-Cuda, comes with NVIDIA drivers pre-installed. There is very little reason to use this if you are not using GPU-flavors.

Snowflake images

These images you should probably not use if you don't have a really good reason. You might be better of creating your own image

Is there any images that you think we should add don't hesitate contacting


This is a really small image which can be used to boot instance really fast. This can be useful to doing tests in Pouta, like does the network work or how fast can one launch an instances. You should not use this for persistent VMs, and you should always delete the instance when you are done with testing. There is very little reason for end-users using this image and if you are unsure, CentOS and Ubuntu are a better choice 99% of the time.


Ubuntu-14.04 has been at End of Standard Support for some time and will go EOL in 2022. We recommend to use newer Ubuntu images.


You probably don't want to use this if you are not sure. We will most likely remove this image in the near future since it is getting quite out of date.