I've written this post as a draft sometime ago, but forgot to post it. The reason I looked into it was to find out how DPDK physically works as the OS/Device level and how it bypasses the network stack. So, when you attach a PCIe NIC to your Linux server, you expect traffic will flow … Continue reading How NICs work ? a quick dive !
Passthrough has became more and more popular with time. It started initially for simple PCI device assignment to VMs and then grew to be part of high performance network realm in the Cloud such as SR-IOV, Host-level DPDK and VM-Level DPDK for NFV. In Openstack, if you need to passthrough a device on your compute … Continue reading PCI passthrough: Type-PF, Type-VF and Type-PCI
Deployment tools for Openstack have become very popular, including the very well known Openstack-Ansible. It makes deploying a Cloud an easy task, at the expense of losing access to the insights of "Behind the Scenes" of your your Cloud deployment. If you have had to configure neutron manually, you would have come across the following … Continue reading VNI Ranges: What do they do ?
Openstack Neutron provides by default some protections for your VMs' communications, those protections verify that VMs can not impersonate other VMs. You can easily see how it does that by checking the flow rules in an OVS deployment using: ovs-ofctl dump-flows br-int If you look for a certain qvo port (or the port number, depending … Continue reading Port security in Openstack
It always feels good to know that something I've tried to explain is actually helping people , this truly made my day
From the title, this is obviously a very common scenario that you may want to do. One thing that we rarely think about though is "backends" for the attached volumes when we create volumes. When you create a volume, the volume is created on a cinder backend and kept attached to this backend until it's … Continue reading Migrating VMs with attached RBDs
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