Accelerated Networking with H-series VMs on Azure for older OS distributions
The accelerated networking update for the HPC SKUs on Azure has caused problems for older OS distributions or any MPI versions that do not use the latest UCX. This is due to inconsistent naming for the IB devices. My recent patch to rdma-core can be used to provide consistent naming with udev rules. This following script can be used when building an image:
yum install -y cmake libnl3-devel git clone https://github.com/linux-rdma/rdma-core.git cd rdma-core bash build.sh cp build/bin/rdma_rename /usr/lib/udev/ cat <<EOF >/etc/udev/rules.d/60-ib.rules # Accelnet board ACTION=="add", ATTR{board_id}=="MSF0010110035", SUBSYSTEM=="infiniband", PROGRAM="rdma_rename %k NAME_FIXED mlx5_an0" # HBv2 board ACTION=="add", ATTR{board_id}=="MT_0000000223", SUBSYSTEM=="infiniband", PROGRAM="rdma_rename %k NAME_FIXED mlx5_ib0" # HC board ACTION=="add", ATTR{board_id}=="MT_0000000010", SUBSYSTEM=="infiniband", PROGRAM="rdma_rename %k NAME_FIXED mlx5_ib0" EOF
This will name the accelerated networking mlx5_an0 and the infiniband to mlx5_ib0. Now, you can use the older MPI/UCX versions by setting:
export UCX_NET_DEVICES=mlx5_ib0:1
The script includes rules that will work for HB, HC, HBv2 and NDv2.
Published on:
Learn moreRelated posts
Introducing the Azure Cosmos DB Plugin for Cursor
We’re excited to announce the Cursor plugin for Azure Cosmos DB bringing AI-powered database expertise, best practices guidance, and liv...
Azure DevOps Remote MCP Server (public preview)
When we released the local Azure DevOps MCP Server, it gave customers a way to connect Azure DevOps data with tools like Visual Studio and Vis...
Azure Cosmos DB at FOSSASIA Summit 2026: Sessions, Conversations, and Community
The FOSSASIA Summit 2026 was an incredible gathering of developers, open-source contributors, startups, and technology enthusiasts from across...
Dataverse: Avoid Concurrency issues by using Azure Service Bus Queue and Azure Functions
Another blog post to handle the concurrency issue. Previously, I shared how to do concurrency via a plugin in this blog post and also how to f...
March Patches for Azure DevOps Server
We are releasing patches for our self‑hosted product, Azure DevOps Server. We strongly recommend that all customers stay on the latest, most s...
Azure Developer CLI (azd): Debug hosted AI agents from your terminal
New azd ai agent show and monitor commands help you diagnose hosted AI agent failures directly from the CLI. The post Azure Developer CLI (azd...
A Look Ahead at Azure Cosmos DB Conf 2026: From AI Agents to Global Scale
Join us for Azure Cosmos DB Conf 2026, a free global, virtual developer event focused on building modern applications with Azure Cosmos DB. Da...
Announcing general availability of Azure Confidential Computing (ACC) virtual machines for U.S. government environments
Government agencies have an increased need for secure, verifiable, and compliant cloud environments that adhere to data sovereignty regulation...