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Chapter 4 New Features and Changes

Table of Contents

The following new features and changes are included in Oracle Linux 7.9. These features generally apply to the x86_64 and Arm (aarch64) platforms, unless otherwise specified. For information that applies specifically to the Arm platform, see Chapter 7, Release-Specific Information for Oracle Linux 7.9 (aarch64).

For information about the new features and changes in the initial release of Oracle Linux 7, see Oracle® Linux 7: Release Notes for Oracle Linux 7.

4.1 Red Hat Compatible Kernel

Oracle Linux 7.9 includes the following Red Hat Compatible Kernel (RHCK) features and changes.

4.1.1 BTRFS Deprecated in RHCK

Starting with Oracle Linux 7.4, the Btrfs file system type is deprecated in RHCK. Note that the Btrfs file system is fully supported with UEK R4 and later UEK releases.

4.1.2 EDAC Driver for Intel ICX Systems Added

The Error Detection and Correction (EDAC) driver has been added to Intel ICX systems in this release. This driver enables error detection on these systems, as well as reports any errors to the EDAC subsystem.

4.1.3 Mellanox ConnectX-6 Dx Network Adapter Support Added

Oracle Linux 7.9 adds the PCI IDs of the Mellanox ConnectX-6 Dx network adapter to the mlx5_core driver. For systems that use this adapter, the mlx5_core driver is loaded automatically. Support for this feature was previously made available for UEK R6 and UEK R5U4, but was only available as a technology preview in earlier Oracle Linux releases.

4.2 DIF/DIX (T10 P1) Support for Specified Hardware

SCSI T10 DIF/DIX is fully supported on hardware that has been qualified by the vendor, provided that the vendor also fully supports the particular host bus adapter (HBA) and storage array configuration. Note that DIF/DIX is not supported on other configurations such as for use on a boot device or a virtualized guest.

Note

Support for DIF/DIX is a technology preview for any HBAs and storage arrays that are not qualified and are not fully supported by the vendor. To determine whether DIF/DIX is supported by a particular hardware vendor, refer to that vendor's support information for the latest status.

4.3 FreeRDP Updated to Version 2.1.1

The FreeRDP feature for the Remote Desktop Protocol (RDP) is updated from version 2.0.0 to version 2.1.1 in this release. This version of FreeRDP includes new RDP options for the current Microsoft Windows terminal server version. Several security issues are also fixed in FreeRDP 2.1.1.

4.4 Pacemaker Updated to Version 1.1.23

The Pacemaker cluster resource manager is updated in this release to version 1.1.23. This version of Pacemaker provides numerous bug fixes over the previous version.

4.5 Metrics for per-thread Available for Historical Analysis

Capability for optionally enabling logging of the per-thread and per-process performance metric values in the Performance Co-Pilot (PCP) is now included in the pcp-zeroconf package and the pmieconf utility. In previous releases, the per-process metric values were included in the pcp-zeroconf package and logged by pmlogger. Because some analysis situations also require per-thread values, per-thread metrics are now available for historical analysis. To enable this feature, use the following command:

# pmieconf -c enable zeroconf.all_threads

4.6 SCAP Security Guide Now Correctly Disables Services

With this update, the SCAP Security Guide (SSG) profiles correctly disable and mask services that should not be started. This feature enhancement guarantees that disabled services are not inadvertently started as a dependency of another service. Prior to this change, SSG profiles, such as the U.S. Government Commercial Cloud Services (C2S) profile, only disabled the service. As a result, services that are disabled by an SSG profile cannot be started unless you unmask them first.

4.7 Technology Preview

For RHCK, the following features are currently under technology preview.

Features that are currently under technology preview in UEK R6 are described in Unbreakable Enterprise Kernel: Release Notes for Unbreakable Enterprise Kernel Release 6.

Systemd: Importd features for container image imports and exports.
File Systems:
- Block and object storage layouts for parallel NFS (pNFS).
- DAX (Direct Access) for direct persistent memory mapping from an application. This feature is under technical preview for the ext4 and XFS file systems.
- OverlayFS remains in technical preview.
Kernel:
- Extended Berkeley Packet Filter tool (eBPF) system call for tracing.
- Heterogeneous memory management (HMM). A non-CPU device processor may read system memory using the unified system address space. To enable this feature, add experimental_hmm=enable to the kernel command line.
- kexec. The kexec system call enables loading and booting into another kernel from the currently running kernel. Hardware initialization is not performed during a kexec boot, significantly reducing reboot time.
- No-IOMMU mode virtual I/O feature.
  
  Note
  
  This mode lacks the I/O management that is provided by an IOMMU and is not secure.
- Traffic Control (TC) Hardware offloading. This feature enables select network traffic processing to be executed directly in the hardware.
Networking:
- Cisco VIC InfiniBand kernel driver, which provides similar functionality to RDMA on proprietary Cisco architectures.
- Single-Root I/O virtualization (SR-IOV) in the qlcnic driver.
- Cisco proprietary User Space Network Interface Controller in UCM servers provided in the libusnic_verbs driver.
- The flower traffic control classifier, with off-loading support.
- Trusted Network Connect. This feature enables you to verify an endpoint against existing network access policies before allowing network access.
Storage:
- Multi-queue I/O scheduling for SCSI (scsi-mq). Note that this functionality is disabled by default. To enable the feature, add scsi_mod.use_blk_mq=Y to the RHCK kernel command line.
- SCSI-MQ as a preview with the qla2xxx driver and lpfc devices.
- Plug-in for the libStorageMgmt API used for storage array management. The libStorageMgmt API is now supported, but the plug-in is under technology preview.

4.8 Compatibility

Oracle Linux maintains user space compatibility with Red Hat Enterprise Linux (RHEL), which is independent of the kernel version that underlies the operating system. Existing applications in userspace continue to run unmodified on Unbreakable Enterprise Kernel Release 6 (UEK R6) and no re-certifications are required for RHEL certified applications.

To minimize the impact on interoperability during releases, the Oracle Linux team works closely with third-party vendors whose hardware and software have dependencies on kernel modules. The kernel ABI for UEK R6 will remain unchanged in all subsequent updates to the initial release. UEK R6 contains changes to the kernel ABI relative to UEK R5 that require recompilation of third-party kernel modules on the system. Before installing UEK R6, verify support status for the release with your application vendor.