Many run CirrOS on cloud for testing, learning, training or even demos. Its fast, lightweight, agile OS that specializes in running on a cloud. OpenStack based cloud deployments are mostly tested using CirrOS. It is versatile for various test scenarios, Be it network or orchestration. Everyone loves cirros on cloud but what about virtualization?
Yes, Virtualization Platforms are still there and many use them. I want to do some testing on my virtualization platform (vmware,kvm,virtual-box), Can I use CirrOS image? The answer is yes, The official CirrOS image works with any virtualization platform you name it. However, There is a small problem. It comes with cloud-init configured.
Then what? Cloud-init is a package that contains utilities for early initialization of cloud instances using metdata services of the cloud. When you start the CirrOS on virt, Before you get login screen, cloud-init is executed and it starts finding the metadata server. If metedata server not found, retries connecting it 20 times.
This 20 retries is equal to 20 seconds delay. So the official image of CirrOS will take 20 + seconds to boot on virtualization platforms. 20 seconds is huge for impatient system administrator like me. Correct?
Solution? Use this virtualization friendly virt-cirros image, It will boot within few seconds and is specially customized to run on virtualization platforms. cloud-init is disabled, dhcp timeout reduced to 1 second from 3 minutes :)
Download Link : https://github.com/eprasad/virt-cirros/raw/master/virt-cirros-0.3.4-x86_64-disk.img md5sum : 23a57eae58e8993e3ca22b2fe98ad1d4