Networking and Storage Configuration Flashcards
7 cards from real COA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Networking and Storage Configuration flashcards as text
Which command migrates a Cinder volume to a different storage backend without detaching it from an instance?
Answer: cinder retype --migration-policy on-demand
cinder retype with --migration-policy on-demand changes the volume type and triggers a live migration to the target backend.
In Neutron, which DHCP option must be set on a subnet so instances automatically learn the default gateway?
Answer: gateway_ip
The gateway_ip field on a subnet is sent as DHCP option 3 (router) so instances configure their default route automatically.
Which Swift command uploads an object and sets a custom metadata header named 'X-Object-Meta-Project'?
Answer: swift upload -H 'X-Object-Meta-Project: value' container object
The -H flag on swift upload passes raw HTTP headers, allowing custom X-Object-Meta-* metadata to be set at upload time.
What is the effect of setting 'net.ipv4.ip_forward=1' on a Neutron network node?
Answer: Allows the kernel to route packets between network interfaces, required for L3 NAT
IP forwarding must be enabled in the kernel so the L3 agent can perform routing and SNAT between tenant and external networks.
Which Cinder operation creates a point-in-time copy of a volume that can later be used to create new volumes?
Answer: openstack volume snapshot create
openstack volume snapshot create captures the state of a volume at that moment, which can then be used as a source for new volumes.
Which Neutron agent handles the lifecycle of network namespaces for DHCP on each network?
Answer: neutron-dhcp-agent
The neutron-dhcp-agent creates a dnsmasq process inside a dedicated network namespace for each DHCP-enabled subnet.
In a Ceph-backed Glance + Cinder deployment, what optimization allows Cinder to create volumes from images without transferring data through the API host?
Answer: Copy-on-write cloning via librbd
When both Glance and Cinder use the same Ceph pool, the Cinder RBD driver clones the image as a copy-on-write child volume instantly without data movement.