On this page
Context and Problem Statement
Storage traffic shares the same fabric as application and management traffic. We need to decide whether storage access should be isolated in a dedicated segment (VLAN/VXLAN) and if QoS is required to protect storage performance.
Decision Drivers
- Storage bandwidth and latency requirements for Ceph and OpenShift workloads.
- Prevent storage traffic from impacting application or management paths.
- Compatibility with DC 3.0 and future SDN segmentation.
Considered Options
- No storage traffic segregation.
- VLAN segmentation for storage traffic (optional QoS).
- VXLAN segmentation for storage traffic (optional QoS).
Decision Outcome
Chosen option: VXLAN segmentation for storage traffic with mandatory QoS policy.
Implementation baseline:
- Storage traffic runs in dedicated storage VRF/VNI segments, separate from application and management paths.
- QoS classes for storage replication and storage client traffic are mandatory and validated in network evidence runs.
- Storage-path SLO checks are part of WP-01 acceptance and rollout readiness gates.
Pros and Cons of the Options
Option 1 – No segregation
Pros
- Simplest network configuration and lowest initial effort.
Cons
- Higher risk of contention between storage and application traffic.
Option 2 – VLAN segmentation
Pros
- Clear isolation with minimal overlay complexity.
Cons
- VLAN scale limits and coordination overhead.
Option 3 – VXLAN segmentation (chosen)
Pros
- Flexible segmentation with room for growth.
Cons
- Additional overlay complexity and operational tooling requirements.