#Nova

Preface Would you need an Upgrade? Plan the upgrade Methods of upgrades Parallel Cloud Advantages Disadvantages Rolling upgrade Advantages Do an upgrade in Staging Backup Upgrade plan Upgrade Day01 Day02 Customer Feedback Further Reading Preface Upgrading a public cloud to the next stable release is a Nightmare for the Operations Team. We are using Openstack as our cloud software. [Read More]

No valid hosts found Real scenario Oh, yeah here it is Issue Finding Further reading No valid hosts found I am sure, everyone of you found this error in your API call OR Horizon instance intiation. But what is it exactly?, Well the error says no valid hosts found which is clear right? You dont have enough computing resource to launch the new virtual machine. It could be vCPU, vRAM, vDISK. [Read More]

What is Live Migration Why we need a Live Migration Host Failure Maintanance mode Optimal resource usage How a Live migration happening ? Pre-migration Reservation Iterative pre-copy Stop and Copy Commitment Pitfalls Abort ? Futher reading What is Live Migration Live-migrating an instance means moving its virtual machine to a different OpenStack Compute server while the instance continues running. When you are operating a public cloud OR private cloud you need to do this for many reasons. [Read More]

What is Python Virtualenvironment Installation Install pip Install needed Python modules Set a Directory for your Environments Add it on your bashprofile Testing the virtualenvironment Activate and Deactivate the environment Remove the Virtualenvironment Futher Reading What is Python Virtualenvironment Python applications will often use packages and modules that don’t come as part of the standard library. Applications will sometimes need a specific version of a library, because the application may require that a particular bug has been fixed or the application may be written using an obsolete version of the library’s interface. [Read More]

Preface Taking snapshot Download the Image Create Image in the Destination Project Boot the new Instance Preface Cloud Administrators, or End users need to migrate instances from one Porject to another. Or, a Cloud to another cloud. There is multiple ways to achieve this. The easiest way to use snapshot feature and do the migration. Shutdown the Virtual Machine $ openstack server list +--------------------------------------+------------+--------+------------------------------+------------+ | ID | Name | Status | Networks | Image Name | +--------------------------------------+------------+--------+------------------------------+------------+ | c41f3074-c82a-4837-8673-fa7e9fea7e11 | myInstance | ACTIVE | private=10. [Read More]

Preface List the available hypervisor list to add under this zone. Now, we are going to add hypervisor “compute1” under Ezone-IND Preface People may have little bit of confusion about Host Aggregates and Availabaility Zones in Nova. Here I am trying to explain how these things are worked together. All configuration options aer based on Icehouse release of Openstack. A host aggregate is a grouping of hosts with associated metadata. [Read More]

I want to force openstack to resize every instance on the same host if it is possible to do. How can I do that? Before that, why should I do that. Here, you have a use case, you are on a private cloud and running some critical virtual machines in a very limited resources. You should take a turn to do this. Add the following lines in /etc/nova/nova.conf allow_resize_to_same_host=True scheduler_default_filters=AllHostsFilter Restart Services [Read More]