A tool that's less known-about for cinder is cinder-manage. You might have run into it during upgrades. The most common use case is cinder-manage db sync This is normally executed during upgrades to bring the database to the latest version, or to create the schema for a new installation. But there's actually additional usages for … Continue reading cinder-manage: Did you know about it ?
The Openstack User Group for Southwestern Ontario is finally here ! The group will focus on allowing Openstack users in the SWO area to exchange experiences and knowledge of Openstack as well as a way to socialise with fellow Openstackers If you'r in the area, join us . Events will be soon posted on the … Continue reading Openstack SWO User Group is here !
So, you've managed to deploy OpenStack in a production environment, and now you would like to make sure that your precious investment in hardware doesn't get ruined by poor performance tuning. You might want to consider reading this post. You have to remember first that OpenStack is a Cloud Computing Enabler framework, i.e. none of … Continue reading OpenStack Performance tuning
You might find yourself in a position where you need to restrict access by tenants to specific external networks. In Openstack there's the notion that external networks are accessible by all tenants and anyone can attach their private router to it. This might not be the case if you want to only allow specific users … Continue reading Private External Networks in Neutron
If you run into an issue where a Cinder volume you attached to a VM can not be deleted even after detaching it from the VM, and when you look into the logs you find something like ERROR cinder.volume.manager ....... Unable to delete busy volume. or WARNING cinder.volume.drivers.rbd ......... ImageBusy error raised while deleting rbd … Continue reading Busy Cinder volumes & Ceph
You might find yourself in a scenario where you need to backup a CEPH volume attached to an Openstack Instance. CEPH snapshots come automatically to mind as the "state-in-time" solution. Once you take a CEPH snapshot, you can export it and backup the volume either as a physical file or at the file system level, … Continue reading Ceph RBD snapshots for an attached volume
DHCP requests are broadcast requests sent by the VM to its boradcast domain. If a DHCP server exists in this domain, it will respond back providing a DHCP IP lease following the DHCP protocol. In openstack, the same procedure is followed. A VM starts by sending its DHCP request to its boardcast domain which goes … Continue reading VM getting a DHCP address
If you are expanding your ceph cluster with extra nodes. You will need to prepare the node to have ceph installed and prepare the OSDs to be part of the ceph cluster. In order to do this, you can use ceph-deploy to install ceph on the new nodes and prepare/activate the osds on it. The … Continue reading Adding a new node to ceph
So far we have only spoken about VM communication when they belong to the same network. But what happens when the VM has to communicate with another VM on a different network. The common rule of networking is that changing networks requires routing. This is exactly what neutron does to allow those kinds of VMs … Continue reading VM to VM communication: different networks
In the last post, we spoke about VM to VM communication when they belong to the same network and happen to get deployed to the same host. This is a good scenario, but in a big openstack deployment, it's unlikely that all your VMs belonging to the same network will end up on the same … Continue reading VM to VM communication, same network, different compute hosts