VIO Server 3.1

Basic Information

IBM Virtual I/O Server (VIOS) 3.1 is a virtualization software layer designed for IBM Power Systems. It enables the sharing of physical I/O resources among client logical partitions (LPARs).

• Model: Virtual I/O Server (VIOS)
• Version: 3.1 (includes sub-versions like 3.1.0, 3.1.1, 3.1.3, 3.1.4, 3.1.4.50)
• Release Date: November 9, 2018 (for VIOS 3.1.0).
• Minimum Requirements: Refer to Technical Requirements section.
• Supported Operating Systems (Base): AIX 7.2 TL3 (for 3.1.0) and AIX 7.2 TL4 (for 3.1.1).
• Supported Operating Systems (Client LPARs): AIX and Linux.
• Latest Stable Version: VIOS 3.1.4.50 is a recent fix pack level.
• End of Support Date: End of normal support for VIOS 3.1.4 is April 30, 2026. A service extension for VIOS 3.1.4 is available until April 30, 2028.
• End of Life Date: Not explicitly stated as a distinct "End of Life" date, but end of support dates are provided. Older VIOS 2.x versions reached their last service extension end on June 30, 2023.
• Auto-update Expiration Date: Not specified.
• License Type: Part of PowerVM Editions, an IBM hardware feature.
• Deployment Model: Deployed as a dedicated logical partition (LPAR) on IBM Power Systems.

Technical Requirements

IBM VIOS 3.1 operates on IBM Power Systems hardware, requiring specific configurations for optimal performance and functionality.

• RAM: Minimum 4 GB. For Shared Storage Pools (SSP), 16 GB is recommended.
• Processor: Minimum 1 CPU with guaranteed entitlement. 2 processors are generally recommended.
• Storage: Minimum 30 GB for the root volume group (rootvg) for installation. 100 GB is often recommended for rootvg. An additional disk is required for alternate disk upgrades.
• Display/Ports: Standard server console access or network access. Supports USB flash drive installation.
• Operating System: The VIOS itself is based on AIX 7.2 TL3 or later.
• Hardware: Requires IBM Power Systems servers. Supports POWER7+ (D models) or later, POWER8, and POWER9 processors. VIOS 3.1.3 specifically requires POWER8 or later.
• Firmware: For POWER8 systems, firmware level FW860.20 or later is required. For POWER9 systems, FW910 or later is necessary.
• Hardware Management Console (HMC): An HMC is required for creating logical partitions and assigning resources to the VIOS.

Analysis of Technical Requirements: VIOS 3.1 demands a robust Power Systems environment, reflecting its role in virtualizing critical I/O resources. The memory and storage recommendations, particularly for SSPs, highlight the need for adequate provisioning to ensure stability and performance. The hardware and firmware prerequisites emphasize compatibility with modern Power Systems architectures, moving away from older generations. The reliance on HMC underscores its enterprise-grade management framework.

Support & Compatibility

IBM VIOS 3.1 offers a defined support lifecycle and broad compatibility with IBM Power Systems hardware and client operating systems.

• Latest Version: VIOS 3.1.4.50 is a current fix pack release.
• OS Support (Base): Based on AIX 7.2 TL3/TL4.
• OS Support (Client LPARs): Supports AIX and Linux client logical partitions.
• End of Support Date: Normal support for VIOS 3.1.4 ends on April 30, 2026. An extended service option for 3.1.4 is available until April 30, 2028.
• Localization: Supports installation of additional language file sets post-initial setup.
• Available Drivers: Incorporates device driver enhancements from AIX 7.2. The AIXPCM driver is recommended and replaces the older SDDPCM driver.
• Hardware Compatibility: Compatible with IBM Power Systems featuring POWER7+ (D models) or later, POWER8, and POWER9 processors. VIOS 3.1.3 requires POWER8 or newer.

Analysis of Overall Support & Compatibility Status: VIOS 3.1 maintains a strong compatibility stance with recent and current IBM Power Systems hardware, leveraging the stability and features of AIX 7.2. The clear end-of-support dates allow for proactive planning and migration strategies. The transition to AIXPCM drivers simplifies maintenance by integrating updates with the operating system. Support for both AIX and Linux client LPARs ensures versatility in virtualized environments.

Security Status

IBM VIOS 3.1 integrates several security features and benefits from its AIX 7.2 base, though it is subject to ongoing vulnerability management.

• Security Features:
  • Based on a modernized and hardened AIX 7.2 operating system, which includes software cleanup (removal of old software, bundled solutions, and outdated Java versions).
  • Enhancements in disk quorum hardening and improved error handling contribute to system resiliency.
  • Utilizes SHA-256 for password algorithms and supports long passwords (up to 255 characters).
  • Offers Logical Volume Manager (LVM) encryption for rootvg and dump devices.
  • Supports encryption of physical volumes using the SCSI protocol via the hdcryptmgr command.
  • Insecure services like rexec, rsh, telnet, and ftp are disabled by default.
  • Live Partition Mobility (LPM) operations on POWER9 systems benefit from on-chip compression/encryption.
• Known Vulnerabilities:
  • Recent critical vulnerabilities (e.g., CVE-2025-36250, CVE-2025-36251) have been identified in NIM server services (nimesis and nimsh) affecting VIOS 3.1 (and 4.1), potentially allowing remote arbitrary command execution. These address additional attack vectors for previously patched vulnerabilities.
  • Other vulnerabilities have been reported for specific fix pack versions (e.g., 3.1.3.17, 3.1.3.8, 3.1.3.2), which are typically addressed through patches.
• Blacklist Status: No general blacklist status is indicated.
• Certifications: Guidance for secure configuration is available through CIS (Center for Internet Security) specifications for VIOS servers.
• Encryption Support: LVM encryption for rootvg and dump devices, physical SCSI volume encryption, and LPM with on-chip encryption.
• Authentication Methods: Strong password policies with SHA-256 algorithm and extended password length support.
• General Recommendations: Regularly apply the latest fix packs and security updates. Follow CIS benchmarks for secure configuration, including resizing filesystems and regenerating SSH host keys after installation.

Analysis on the Overall Security Rating: IBM VIOS 3.1 benefits from a hardened AIX 7.2 base, incorporating modern security practices such as strong password algorithms, encryption options, and the disabling of insecure services by default. However, like any complex enterprise software, it is subject to ongoing discovery of vulnerabilities. The presence of recent critical CVEs highlights the importance of timely patching and adherence to IBM's security advisories. Following recommended security practices, including regular updates and configuration hardening based on CIS benchmarks, is crucial for maintaining a strong security posture.

Performance & Benchmarks

IBM VIOS 3.1 focuses on enhancing performance and efficiency through its updated base and specific feature improvements.

• Benchmark Scores: Specific, publicly available benchmark scores are not consistently detailed in the provided information. Performance improvements are generally described qualitatively.
• Real-world Performance Metrics:
  • Device driver enhancements in AIX 7.2 contribute to improved performance and efficiency.
  • Live Partition Mobility (LPM) performance is significantly improved on POWER9 systems due to the use of on-chip compression and encryption functionality during LPAR migration.
  • Features like enhanced MPIO (Multi-Path I/O) offer faster Fibre Channel failover and optimized FPIN traffic.
  • Reduced boot time contributes to overall system availability and efficiency.
  • The move to a PostgreSQL database for Shared Storage Pool (SSP) management (from Solid) offers a more robust and scalable solution.
• Power Consumption: Not explicitly detailed.
• Carbon Footprint: Not explicitly detailed.
• Comparison with Similar Assets: Compared to its predecessor, VIOS 2.x (based on AIX 6.1), VIOS 3.1 (based on AIX 7.2) offers significant advantages in modernization, security, and resiliency. It is better equipped to exploit newer POWER hardware features, leading to improved virtualization performance and capabilities.

Analysis of the Overall Performance Status: VIOS 3.1 delivers notable performance enhancements primarily through its updated AIX 7.2 base and optimized features for modern Power Systems. Key areas of improvement include I/O operations, LPM efficiency, and overall system responsiveness. While specific benchmark numbers are not readily available, the architectural changes and feature updates indicate a clear focus on maximizing the performance of virtualized workloads on IBM Power hardware. The ability to leverage POWER9's on-chip capabilities for LPM is a significant advantage for dynamic environments.

User Reviews & Feedback

User feedback on IBM VIOS 3.1 highlights its advancements while noting the complexities of major version upgrades.

• Strengths:
  • Praised for modernization, enhanced security, and improved resiliency due to its AIX 7.2 base.
  • New "cloud-ready" features, such as iSCSI virtualization with MPIO support, are well-received.
  • The ability to install via USB flash drive is a practical enhancement.
  • Device driver improvements and a smaller software footprint contribute to efficiency and shorter maintenance windows.
  • The viosupgrade tool is provided to assist in migration, aiming for a simpler and more reliable process.
  • Generally considered "rock solid" once installed and running, with no massive functional changes that require relearning.
• Weaknesses:
  • Upgrading from VIOS 2.x to 3.1 is considered a "major upgrade" and involves a "new and complete overwrite install," which can be complex and time-consuming.
  • Some users have reported challenges and even failures during the upgrade process, necessitating careful planning, extensive backups, and potential manual recovery.
  • Early versions of VIOS 3.1 had bugs, leading to recommendations to wait for later fix packs before upgrading production systems.
  • The removal of IVM (Integrated Virtualization Manager) means users must install a proper VIOS.
• Recommended Use Cases:
  • Essential for virtualizing I/O resources for AIX and Linux LPARs on IBM Power Systems.
  • Highly recommended for environments looking to exploit the full capabilities and performance of newer POWER hardware (POWER8, POWER9).
  • Ideal for organizations seeking improved security, resiliency, and modernized virtualization features.

Summary

IBM Virtual I/O Server (VIOS) 3.1 represents a significant evolution in IBM's PowerVM virtualization stack, built upon a modernized AIX 7.2 base. Released in November 2018, it brings substantial improvements in security, resiliency, and performance, particularly for IBM Power8 and Power9 systems. Key strengths include enhanced device drivers, native compatibility modes for newer processors, and new "cloud-ready" features like iSCSI virtualization with MPIO support. Security is bolstered through a cleaner software footprint, stronger password algorithms, LVM encryption, and the disabling of insecure services by default. Performance benefits from these architectural updates, including faster Live Partition Mobility (LPM) operations leveraging POWER9's on-chip capabilities and reduced boot times.

However, the upgrade process from previous VIOS 2.x versions to 3.1 is not a simple update but a complete overwrite installation, which users report can be complex and prone to issues if not meticulously planned and executed. This necessitates thorough preparation, including comprehensive backups and potentially using tools like viosupgrade. While the latest stable versions, such as VIOS 3.1.4.50, address many initial bugs, ongoing vigilance regarding security vulnerabilities and applying timely patches remains critical, as evidenced by recent CVEs affecting NIM services.

Overall, VIOS 3.1 is a robust and essential component for modern IBM Power Systems environments, offering a secure, resilient, and high-performing platform for virtualized AIX and Linux workloads. Its end of normal support for version 3.1.4 is set for April 30, 2026, with an extended service option until April 30, 2028, providing a clear roadmap for lifecycle management. Organizations running on compatible Power Systems hardware are strongly encouraged to migrate to VIOS 3.1 (or later) to leverage its advancements and maintain supported configurations.

Note: The information provided is based on publicly available data and may vary depending on specific device configurations. For up-to-date information, please consult official manufacturer resources.