# Roadrunner SMB — Known Limitations **Last Updated**: 2026-04-15 This document describes known limitations, constraints, and explicitly unsupported features in the current release. Read this before deploying for production use. --- ## Deployment and Topology ### Fixed cluster size The Marketplace offering deploys a fixed 2–4 node cluster. Cluster size is controlled by AWS infrastructure (ASG/ECS); there are no scaling controls in the Admin UI. **Validated deployment range**: 1–4 nodes. Deployments outside this range are not tested and not supported. ### Minimum 2 Availability Zones required Subnets must span at least 2 AZs. Single-AZ deployments are not supported. ### Scaling is infrastructure-managed only Cluster size changes are performed by updating CloudFormation parameters. There is no in-product resize capability. ### No cross-region or DR support Roadrunner SMB is a single-region deployment. Cross-region replication and disaster recovery configurations are not supported. --- ## Active Directory ### Single domain only One Active Directory domain per deployment. Cross-domain trust scenarios are not supported. ### Leave Domain not supported Leaving the Active Directory domain from the Admin UI is not supported. To change domain membership, redeploy the appliance via CloudFormation. ### Guest access not supported All SMB access requires Active Directory authentication. Guest or anonymous access is not supported. --- ## SMB Protocol Features The following SMB features are not supported in the current release: | Feature | Status | |---|---| | SMB Multichannel | Not supported | | SMB Direct (RDMA) | Not supported | | SMB Compression | Not supported | | SMB Encryption (SMB-layer) | Not supported (network-layer encryption via TLS/VPN is supported) | | Persistent Handles (SMB 3.x) | Not supported | | Named Pipes / RPC Endpoints | Not supported (file sharing only) | | DFS Namespaces | Not supported | | Shadow Copies (VSS) | Not supported | | Quotas | Not supported | | File Change Notifications | Limited (standard SMB notify; not all change types) | --- ## Networking ### Admin UI transport In Marketplace (multi-AZ) deployments, the Admin UI is served via the ALB on port 443 (HTTPS). The ALB terminates TLS; internal traffic from the ALB to RRSMB nodes on port 8888 is not encrypted. In single-node / EasyButton mode, the Admin UI is served directly on port 8888 via the NLB without TLS termination. Recommendation: restrict the `AdminCidr` security group to trusted networks and access the Admin UI only from within a VPN or AWS Direct Connect/private connectivity. ### NLB DNS used for share paths Shares are accessed via the NLB DNS name. Customers who require a custom DNS name should create a CNAME or alias record in their DNS pointing to the NLB DNS name. --- ## Performance ### EFS/NFS backend limitations Roadrunner SMB stores share data on Amazon EFS (NFS). Some file operations have different semantics on NFS compared to a native NTFS filesystem: - `$QUOTA` virtual file is not supported (EFS has no quota enforcement) - NULL DACL behavior differs from native NTFS - Some timestamp precision differences may be observed These are fundamental EFS/NFS backend constraints and are not correctable at the Samba configuration level. ### No file data caching File data read/write operations are not cached; performance depends on EFS throughput and latency. Use EFS Elastic throughput mode (default) for best performance. --- ## Monitoring and Metrics ### Cluster metrics are aggregated, not per-node The Admin UI shows cluster-wide aggregate metrics collected across all active nodes. Per-node metric drilldown is available via the Prometheus endpoint on each node (port 9090 on the task ENI) for advanced diagnostics. ### No external metrics integration There is no built-in integration with Grafana, Datadog, CloudWatch Metrics, or other external platforms. Raw Prometheus metrics are exposed per-node on port 9090. --- ## Admin UI Configuration ### Some settings are environment-variable only The following configuration items are only changeable via CloudFormation environment variables; they are not exposed in the Settings page: - Container CPU/memory limits - EFS throughput mode - Log level (runtime override available via Logs page) - CTDB tuning parameters --- ## Software Updates ### Updates require a CloudFormation stack update There is no in-product auto-update mechanism. To update Roadrunner SMB, update the `BackendImageUri` CloudFormation parameter to the new image tag and run a stack update. The update process performs a rolling node replacement, maintaining at least 2 of 3 nodes serving throughout. --- ## Support ### Support report required for assistance When contacting support, generate a Support Report from the Admin UI **Support** page. First-line support requires the report to begin triage. ### Early-customer support SLA Initial response time: best effort within 1 business day. Formal SLA: to be published. --- ## References - [Quick Start Guide](quick-start.md) - [Deployment Guide](deployment-guide.md) - [Support & Troubleshooting](support-troubleshooting.md)