SQL Server 2025 GA on RHEL 10 & Ubuntu 24.04: A Strategic Leap for Linux Deployments

Microsoft has announced the General Availability (GA) of SQL Server 2025 on Red Hat Enterprise Linux 10 and Ubuntu 24.04, starting with the Cumulative Update 1 (CU1) release. This milestone is more than a routine update; it represents a strategic alignment with the latest enterprise Linux platforms, providing a production-ready path for organizations deploying SQL Server 2025 on modern infrastructure. For enterprises managing multi-cloud or hybrid environments, this GA release solidifies SQL Server's position as a versatile, platform-agnostic database engine, capable of running consistently across Windows Server, various Linux distributions, and containerized environments.

What Changed: From Preview to Production

The GA release transitions SQL Server 2025 from preview builds to a fully supported production version on RHEL 10 and Ubuntu 24.04. This is a critical shift for IT teams, as it validates the platform's stability, security, and performance for mission-critical workloads. The announcement emphasizes the need to update repository configurations to avoid accidentally deploying pre-release software. Organizations must switch from the mssql-server-preview.repo to the mssql-server-2025.repo repository to ensure they are installing the GA version.

This repository update is a procedural but essential step. Installing from the preview repository could result in pre-release builds that lack long-term support, security patches, and performance guarantees. The official documentation provides detailed installation guides for both RHEL and Ubuntu, ensuring a smooth transition for administrators.

Provider Comparison: SQL Server 2025 on Linux vs. Alternatives

When considering database platforms for Linux environments, organizations often evaluate SQL Server against other enterprise databases like PostgreSQL, Oracle, or MySQL. SQL Server 2025 on Linux offers a unique value proposition, particularly for enterprises already invested in the Microsoft ecosystem or those requiring specific SQL Server features like Always On Availability Groups, T-SQL, or integration with Azure services.

Key Differentiators:

1. Consistency Across Platforms: SQL Server 2025 provides feature parity between Windows and Linux, allowing teams to standardize on a single database engine regardless of the underlying OS. This reduces training overhead and simplifies tooling. In contrast, databases like PostgreSQL are inherently Linux-centric, and while they run on Windows, the experience and tooling differ.

2. Pricing and Licensing: SQL Server 2025 on Linux follows the same licensing model as Windows—per-core licensing or Server+CAL. This can be advantageous for enterprises with existing SQL Server licenses, as they can repurpose them for Linux deployments. PostgreSQL, being open-source, has no licensing costs but may require additional investment in commercial support or third-party tools for enterprise features.

3. Integration with Microsoft Ecosystem: For organizations using Azure, Power BI, or other Microsoft services, SQL Server 2025 on Linux offers seamless integration. Features like Linked Servers, PolyBase, and SQL Server Agent are available, which are not native to PostgreSQL or MySQL. Oracle Database on Linux offers similar integration with Oracle Cloud, but at a higher cost and complexity.

4. Performance and Optimization: SQL Server 2025 includes advanced query processing, in-memory OLTP, and intelligent performance tuning. While PostgreSQL has strong performance, especially with extensions like TimescaleDB for time-series data, SQL Server's query optimizer and built-in AI capabilities (e.g., automatic tuning) provide a competitive edge for transactional workloads.

Pricing Considerations:

• SQL Server 2025: Licensing costs can be significant, especially for high-core-count servers. However, the Standard Edition offers a lower-cost option for smaller deployments, while Enterprise Edition includes advanced features like Always On Availability Groups and in-memory OLTP.
• PostgreSQL: No licensing fees, but support contracts (e.g., from EDB or Crunchy Data) can cost $1,000–$5,000 per server annually. Additional costs may arise from tools for backup, monitoring, and high availability.
• Oracle Database: Typically more expensive, with per-core licensing and additional fees for options like RAC or Partitioning. Oracle's Linux support is robust, but the total cost of ownership is often higher.

For enterprises with existing SQL Server investments, migrating to SQL Server 2025 on Linux can be more cost-effective than switching to a new database platform, as it leverages existing skills and tools.

Business Impact: Migration and Operational Considerations

Migrating to SQL Server 2025 on RHEL 10 or Ubuntu 24.04 requires careful planning. The GA release provides a stable target, but organizations must assess their current environment and define a migration strategy.

Migration Pathways:

1. In-Place Upgrade: For existing SQL Server 2017 or 2019 installations on Linux, upgrading to SQL Server 2025 may be possible, but a clean installation is often recommended for production systems to avoid legacy issues.

2. Lift-and-Shift: Moving workloads from Windows Server to Linux can reduce licensing costs and improve flexibility. Tools like the Data Migration Assistant help assess compatibility and recommend fixes.

3. Hybrid Deployments: SQL Server 2025 supports hybrid scenarios where some instances run on Linux and others on Windows, with Always On Availability Groups spanning both platforms. This allows gradual migration and risk mitigation.

Operational Best Practices:

• Repository Management: As noted, updating repositories is crucial. Automate this process using configuration management tools like Ansible or Puppet to ensure consistency across servers.

• Testing: Validate workloads on RHEL 10 or Ubuntu 24.04 in a staging environment. Pay attention to performance differences, especially I/O and network latency, which can vary between Linux distributions.

• Monitoring: Leverage the new Dynamic Management Views (DMVs) for OS-level insights. For example, sys.dm_os_linux_cpu_stats helps correlate SQL Server performance with CPU saturation from other processes, which is vital in shared hosting or containerized environments.

New Features: Contained Availability Groups and Observability

Contained Availability Group (CAG) Database Operations

SQL Server 2025 introduces the ability to create and restore databases directly within a contained availability group (CAG) session. This simplifies database management in high-availability setups. Previously, database creation or restoration required direct access to the primary replica, which could be complex in CAG environments.

How It Works:

• Use the stored procedure sp_set_session_context to enable the feature for a session: EXEC sp_set_session_context @key = N'allow_cag_create_db', @value = 1;
• Only users with the dbcreator role can create databases, and db_owner or sysadmin roles are required for restoration.
• The operation is performed through the CAG listener, ensuring consistency across replicas.

Use Cases:

• DevOps Automation: Scripts can now create test databases directly in a CAG environment without manual intervention on the primary replica.
• Disaster Recovery: Restoring databases from backups can be streamlined, reducing downtime during recovery operations.

Trade-offs: While this feature enhances flexibility, it requires careful permission management to prevent unauthorized database operations. It also assumes that the CAG is properly configured and the listener is accessible.

Enhanced Observability with OS-Level DMVs

SQL Server 2025 on Linux introduces three new DMVs that provide visibility into the underlying OS metrics:

1. sys.dm_os_linux_cpu_stats: Reports CPU usage, saturation, and wait times. This helps distinguish between SQL Server-induced CPU pressure and external processes (e.g., other containers or applications on the same host).

   • Example Query: SELECT * FROM sys.dm_os_linux_cpu_stats;
   • Insight: If CPU saturation is high but SQL Server's own CPU usage is low, investigate other processes or consider CPU isolation techniques.

2. sys.dm_os_linux_disk_stats: Monitors disk I/O, including read/write rates and latency. Critical for diagnosing log flush delays or checkpoint bottlenecks.

   • Example Query: SELECT * FROM sys.dm_os_linux_disk_stats WHERE disk_number = 0;
   • Insight: High latency on log drives may indicate storage tiering issues or noisy neighbors in cloud environments.

3. sys.dm_os_linux_net_stats: Tracks network interface statistics, such as bytes sent/received and packet drops.

   • Example Query: SELECT * FROM sys.dm_os_linux_net_stats;
   • Insight: Useful for troubleshooting replication latency or Always On synchronization issues.

Broader Impact: These DMVs enable a holistic view of performance, aligning with modern DevOps practices where database performance is tied to infrastructure health. For example, in a Kubernetes cluster, these metrics can help correlate SQL Server performance with pod resource limits or node saturation.

Migration Considerations and Cost Analysis

When planning a migration to SQL Server 2025 on Linux, consider the following:

• Licensing: SQL Server 2025 requires per-core licensing. If moving from Windows, ensure your existing licenses are transferable. For new deployments, evaluate the cost against PostgreSQL or MySQL, especially if open-source is a priority.

• Skill Set: SQL Server on Linux uses the same T-SQL and tools (e.g., SQL Server Management Studio, Azure Data Studio). Teams familiar with SQL Server will have a shorter learning curve compared to adopting a new database like PostgreSQL.

• Support: Microsoft provides enterprise support for SQL Server on Linux, including patches and updates. For PostgreSQL, support options vary by vendor, and community support may be sufficient for smaller deployments.

• Performance Benchmarks: Test your workloads on RHEL 10 or Ubuntu 24.04. SQL Server 2025 includes performance improvements, but Linux-specific tuning (e.g., file system choices, I/O scheduler) may be needed. For instance, using XFS or ext4 with appropriate mount options can optimize disk performance.

Conclusion: A Strategic Choice for Enterprise Databases

SQL Server 2025's GA on RHEL 10 and Ubuntu 24.04 is a compelling option for enterprises seeking a robust, secure, and AI-ready database platform. The new features—contained availability group operations and OS-level observability—address real-world challenges in high-availability and performance monitoring. While alternatives like PostgreSQL offer cost advantages, SQL Server's integration with the Microsoft ecosystem and cross-platform consistency provide a strong value proposition for organizations already invested in SQL Server or those requiring specific enterprise features.

For teams considering migration, the key is to start with a pilot project on RHEL 10 or Ubuntu 24.04, validate performance, and update repositories to the GA version. With proper planning, SQL Server 2025 on Linux can deliver the reliability and scalability needed for mission-critical workloads.

References:

• What’s New in SQL Server 2025
• Contained Availability Groups
• SQL Server on Linux Documentation
• GitHub Issues for SQL Server on Linux
• Azure Ideas for SQL Server on Linux