Openstack stores quota usage for tenants in the database in quota_usages table. Nova and cinder have by default their own separate databases and in each database you get a new quota_usages table. The structure of the quota_usages table is as follows +---------------+--------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | … Continue reading Quota usage refresh in Openstack
Using CEPH as a backend for glance images has slowly become the default deployment methodology in many production deployments. It is usually as easy as creating a new pool in ceph ( glance pool) and creating a user to be associated with glance. The glance CEPH user will normally authenticate using cephx and store images … Continue reading Glance and CEPH backend
Cold migrations are an integral piece of any QEMU/KVM deployment. It's cold or "non-live" as you have to power down the VM, move it to the new host and power it back up. Openstack follows the same procedure when it comes to migrating VMs. Cold migrations in Openstack are done via the user running the … Continue reading VM Cold migrations/resizing in openstack
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