What's new for Ubuntu Server 20.04.1 LTS
This revision reflects changes related to Ubuntu Server 20.04.1 LTS.
Booting and shutdown
- Linux® in LPAR mode can now process device configuration data that is stored on the SE, see Device auto-configuration for Linux in LPAR mode.
- The zipl tool can now process Boot Loader Specification (BLS) snippets, see Initial program loader for IBM Z - zipl.
- You can control the secure boot feature with a zipl parameter, see zipl modes and syntax overview and Parameter overview
- Secure boot introduces a new signature verification feature which allows the system firmware to check the authenticity of cryptographic keys to prevent the execution of kernel-space code that is not signed by a trusted key. See Secure boot.
Kernel
- You can now further harden Linux on Z by loading the kernel to a random location see KASLR support.
SCSI over Fibre-Channel
- New sysfs attributes for Fibre Channel hosts provide more information about hosts. The new attributes include fabric_name, which provides the name of the connected Fibre Channel fabric, see Displaying FCP channel and device information.
- You can now obtain diagnostic information about FCP channels, see Obtaining diagnostic data for FCP channels.
- You can now enable the zfcp device driver for two modes of data consistency checking, DIF-only mode and extended mode, which includes DIF and DIX. See Confirming end-to-end data consistency checking.
- You can now examine which FCP connections use IBM Fibre Channel Endpoint Security, see Investigating IBM Fibre Channel Endpoint Security.
Network
- The OSA-Express7S network adapter is now supported, see qeth device driver for OSA-Express (QDIO) and HiperSockets
- TCP segmentation offload is now supported for OSA connections on layer 2. It is available as of z14 for OSA Express6S and newer adapters, see Enabling and disabling TCP segmentation offload.
- If supported by the hardware, you can now configure OSA devices with VNIC characteristics, for example for promiscuous mode, see Advanced packet-handling configuration.
- You can now use internal shared memory devices for fast communication between LPARs within a mainframe system, see Internal shared memory device driver.
System resources
- As of z15 and LinuxONE III, applications can use the Integrated Accelerator for zEnterprise® Data Compression, see Data compression with the Integrated Accelerator for zEDC.
Virtualization
- This publication now includes information for KVM guests. The numerous changes and additions include a new part, KVM virtual server integration. Hypervisor-specific information provides some guidance about the different virtualization environments.
- You can use Ubuntu Server as a host and for guests running in secure execution mode, see Linux as an IBM Secure Execution host or guest and Introducing IBM Secure Execution for Linux
Security
- You can now create reports of cryptographic performance measurement data for cryptographic devices at specified intervals, see zcryptstats - Display crypto statistics.
- You can now create customized cryptographic device nodes, for example, for selective assignment of device nodes to containers, see Creating customized device nodes.
- You can now mark sets of AP queues for handling by device drivers other
than
zcrypt, for example in KVM guests, see Freeing AP queues for KVM guests. - The protected key device driver is extended to handle CCA cipher secure keys and EP11 secure keys, see Protected key device driver.
- You can now read volatile protected key and secure key tokens from sysfs attributes, see Generating volatile protected keys by using the pkey device driver.
- For z14 and later mainframes, CPACF provides hardware-acceleration for SHA3 cipher algorithms, see Hardware-accelerated in-kernel cryptography.
Changed Information
- Checksum offload now supports IPv6, see Configuring hardware checksum offload operations
- PCIe function addresses have changed for environments that support the Alternative Routing-ID Interpretation (ARI) compatible address format, see PCI Express support.
- The CPU Measurement Counter facility is updated to the latest version, see Reading CPU-measurement counters.
- The z/Architecture CPU-measurement facilities support a changed format for specifying counters as raw events, see Reading CPU-measurement counters.
This revision also includes maintenance and editorial changes. Technical changes or additions to the text and illustrations are indicated by a vertical line to the left of the change.
Deleted Information
- NUMA emulation is obsolete, and the corresponding topic has been removed.
- The chapter about suspending and resuming Linux has been removed.
- The src_vipa package is deprecated, and its description has been removed.