Table of Contents

Contents

  1. Introduction
      1. Support lifespan
      2. Official flavor release notes
  2. Get Ubuntu 18.04.2 LTS
    1. Download Ubuntu 18.04.2 LTS
    2. Upgrading from Ubuntu 16.04 LTS or 17.10
  3. New features in 18.04
    1. 32-bit PowerPC Support Dropped
    2. Updated Packages
      1. Linux kernel 4.15
      2. OpenJDK
    3. Security Improvements
      1. Default CIFS/SMB protocol version change in CIFS mounts
      2. Improved UEFI Secure Boot handling for the use of third-party modules
    4. Network configuration
      1. New since 17.10
      2. New since 16.04 LTS
    5. Other base system changes since 16.04 LTS
    6. Ubuntu Desktop
      1. Updates and fixes in 18.04.2
      2. New since 17.10
      3. Other highlights since 16.04 LTS
    7. Ubuntu Server
      1. Updates and fixes in 18.04.2
      2. New since 17.10
      3. Server installer
      4. netplan.io
      5. LXD 3.0
      6. QEMU 2.11.1
      7. libvirt 4.0
      8. DPDK 17.11.x
      9. Open vSwitch 2.9
      10. Chrony
      11. cloud-init
      12. curtin
      13. MAAS
      14. SSSD
      15. Samba
      16. Nginx
      17. PHP
      18. Apache
      19. landscape-client
      20. ubuntu-advantage-tools
      21. s390x-specific enhancements (since 17.10)
      22. OpenStack Queens
      23. ARM64 performance considerations
  4. Known issues
    1. Desktop
    2. Server
  5. Official flavours
  6. More information
      1. Reporting bugs
      2. Participate in Ubuntu
      3. More about Ubuntu

Introduction

These release notes for Ubuntu 18.04.2 LTS (Bionic Beaver) provide an overview of the release and document the known issues with Ubuntu 18.04 LTS and its flavors. For details of the changes applied since 18.04, please see the 18.04.2 change summary. The release notes for 18.04 and 18.04.1 are available as well.

Support lifespan

The 'main' archive of Ubuntu 18.04 LTS will be supported for 5 years until April 2023. Ubuntu 18.04 LTS will be supported for 5 years for Ubuntu Desktop, Ubuntu Server, and Ubuntu Core. Ubuntu Studio 18.04 will be supported for 9 months. All other flavors will be supported for 3 years.

Official flavor release notes

Find the links to release notes for official flavors here.


Get Ubuntu 18.04.2 LTS

Download Ubuntu 18.04.2 LTS

Images can be downloaded from a location near you.

You can download ISOs and flashable images from: http://releases.ubuntu.com/18.04.2/ (Ubuntu Desktop and Server)
http://cdimage.ubuntu.com/ubuntu/releases/18.04.2/release/ (Less Popular Ubuntu Images)
http://cloud-images.ubuntu.com/daily/server/bionic/current/ (Ubuntu Cloud Images)
http://cdimage.ubuntu.com/netboot/18.04.2/ (Ubuntu Netboot)
http://cdimage.ubuntu.com/kubuntu/releases/18.04.2/release/ (Kubuntu)
http://cdimage.ubuntu.com/lubuntu/releases/18.04.2/release/ (Lubuntu and Lubuntu Alternate)
http://cdimage.ubuntu.com/ubuntu-budgie/releases/18.04.2/release/ (Ubuntu Budgie)
http://cdimage.ubuntu.com/ubuntukylin/releases/18.04.2/release/ (Ubuntu Kylin)
https://ubuntu-mate.org/download/ (Ubuntu MATE)
http://cdimage.ubuntu.com/xubuntu/releases/18.04.2/release/ (Xubuntu)

Upgrading from Ubuntu 16.04 LTS or 17.10

To upgrade on a desktop system:

To upgrade on a server system:

Note that the server upgrade will use GNU screen and automatically re-attach in case of dropped connection problems.

There are no offline upgrade options for Ubuntu Desktop and Ubuntu Server. Please ensure you have network connectivity to one of the official mirrors or to a locally accessible mirror and follow the instructions above.


New features in 18.04

32-bit PowerPC Support Dropped

Updated Packages

Linux kernel 4.15

Ubuntu 18.04 ships with a v4.15 based Linux kernel, enabling the latest hardware and peripherals available from IBM, Intel, and others. The 18.04 kernel delivers new features inherited from upstream, including:

We also see notable Ubuntu specific achievements with:

OpenJDK

As of 18.04 release, OpenJDK 10 is the default JRE/JDK. Once OpenJDK 11 reaches GA in September 2018, it will become the default in 18.04.

OpenJDK 8 has moved to universe and will remain available there for the life of 18.04, to provide migration time for packages, custom applications, or scripts that can't be build with OpenJDK 10 or 11. OpenJDK 8 will be updated in 18.04 until Ubuntu 16.04 LTS reaches EOL in April 2021.

Security Improvements

In Ubuntu 18.04 LTS, gcc is now set to default to compile applications as position independent executables (PIE) as well as with immediate binding, to make more effective use of Address Space Layout Randomization (ASLR). All packages in main have been rebuilt to take advantage of this, with a few exceptions.

Mitigations are in place to protect against Spectre and Meltdown. See the Spectre and Meltdown KnowledgeBase article for more details about the remediation and configuration options.

bolt and thunderbolt-tools have been promoted to main to provide security controls for Thunderbolt devices.

Default CIFS/SMB protocol version change in CIFS mounts

Since 17.10, the default SMB protocol used when mounting remote CIFS filesystems via mount.cifs (from the cifs-utils package) changed to 2.1 or higher, depending on what is negotiated with the server. If no version is specified when mounting such a remote share, the following will be logged: 

No dialect specified on mount. Default has changed to a more secure dialect, SMB2.1 or later (e.g. SMB3),
from CIFS (SMB1). To use the less secure SMB1 dialect to access old servers which do not support SMB3
(or SMB2.1) specify vers=1.0 on mount.

Should you encounter compatibility issues, like #1764778 or #1572132, please specify vers=1.0 when mounting the share and please file a bug if that fixes the problem for you.

Improved UEFI Secure Boot handling for the use of third-party modules

Ubuntu now allows you to generate a signing key when needed, as you install third-party (DKMS) modules. On install of a DKMS package, you will be prompted to enter a password that is used to enroll a signing key (an X509 certificate) that will then be used to sign the new kernel modules. The prompts will allow you to enter the same password twice, and describe the steps needed to enroll the new key at the next reboot. For more information, see https://wiki.ubuntu.com/UEFI/SecureBoot/DKMS.

Network configuration

New since 17.10

Teaming support with libteam is available in NetworkManager.

New since 16.04 LTS

The default DNS resolver is systemd-resolved.

ifupdown has been deprecated in favor of netplan.io and is no longer present on new installs. The installer will generate a configuration file for netplan.io in the /etc/netplan directory. This netplan.io configuration in turn renders backend-specific configuration via either systemd-networkd or NetworkManager. Desktop users will see their system fully managed via NetworkManager as it has been the case in previous releases. Server users will now see their network devices managed via systemd-networkd. This only applies to new installations.

Given that ifupdown is no longer installed by default, the commands: ifup and ifdown are also unavailable. Please use the ip command to achieve similar functionality, specifically ip link set $device up and ip link set $device down.

The networkctl command is now available for users to see a summary of network devices. networkctl status will display the current global state of IP addresses on the system. networkctl status $device displays details specific to a network device.

The ifupdown package remains available and supported in Ubuntu main for users that find netplan does not currently meet their networking needs.

For more information about netplan.io, please refer to the manual page using the man 5 netplan command or visit https://netplan.io/.

Scripts in /etc/network/ifup.d and /etc/network/ifdown.d no longer work in this new configuration. For the systemd-networkd backend, similar scripts can be added into subdirectories of /usr/lib/networkd-dispatcher (dormant.d, no-carrier.d, off.d, routable.d), if networkd-dispatcher is installed. Later on, custom scripts can be placed in /etc/networkd-dispatcher and potentially also override the ones in /usr/lib.

Other base system changes since 16.04 LTS

Ubuntu Desktop

Updates and fixes in 18.04.2

New since 17.10

Other highlights since 16.04 LTS

Ubuntu Server

Updates and fixes in 18.04.2

New since 17.10

Server installer

The next generation Subiquity server installer, brings the comfortable live session and speedy install of Ubuntu Desktop to server users at last.

N.B., If you require multipath, full-disk encryption, or the ability to re-using existing partitions, you will want to continue to use the alternate installer which can be downloaded from http://cdimage.ubuntu.com/releases/18.04/release/ As of 18.04.1, the Subiquity server installer now supports LVM, RAID, vlans, and bonds.

netplan.io

ifupdown has been deprecated in favor of netplan.io and is no longer present on new installs. Backend configuration on Ubuntu Server by default is provided by systemd-networkd.

Please see the Network configuration section of these release notes.

LXD 3.0

LXD is the system container manager that ships with all Ubuntu servers.

Ubuntu 18.04 includes the all new LXD 3.0 release, some of the highlights include:

To learn more about LXD 3.0, read the release announcement.

A new external tool called lxd-p2c is also available to turn existing systems into LXD containers.

QEMU 2.11.1

QEMU has been updated to the 2.11.1 release.

See the Changelog for major changes since Artful.

Among many other changes, fixes around Meltdown/Spectre are included. Since fully utilizing these mitigations needs more than just an upgrade, it is recommended to read details at the qemu.org blog post.

QEMU in Ubuntu 18.04 now has rdma support enabled as over the past year much unification in the rdma-core project has occured.

Migrations from former versions are supported just as usual. When upgrading it is always recommended to upgrade the machine types allowing guests to fully benefit from all the improvements and fixes of the most recent version.

libvirt 4.0

libvirt has been updated to version 4.0. See the upstream Changelogs for details since version 3.6 that was in Artful.

The packaging now builds libvirt storage drivers as pluggable libraries. This slims down the installation requirements but some drivers of less general interest will now be found in universe. (ex: gluster, sheepdog, zfs). On the other hand that means that a few formerly integrated features like rbd or zfs now might require you to install the package after upgrade e.g. in this case libvirt-daemon-driver-storage-zfs.

DPDK 17.11.x

Ubuntu includes 17.11.x the latest stable release branch of DPDK.

See the Release Notes for details.

By the new Stable Release exception for DPDK future stable updates to 17.11.x will be made available to Ubuntu 18.04

Open vSwitch 2.9

Open vSwitch has been updated to 2.9.

Please read the release notes for more detail.

Chrony

In Ubuntu 18.04 chrony will replace ntpd as the recommended server for the NTP protocol. See the upstream changelog for an overview of recent changes as well as the FAQ which will help for smooth conversions from NTP.

The comparison among ntp servers by the chrony maintainers may interest some users looking to see a high level reason why this change was made. It does lack the rather new and not yet completely ready ntpsec, but otherwise is a fair analysis.

For simple time sync needs the base system already comes with systemd-timesyncd. Chrony is only needed to act as a time server or if you want the advertised more accurate and efficient syncing.

Going along with this change, ntpd has been demoted from main to universe. ntpd will continue to work but will only receive best-effort security maintenance. When upgrading to Ubuntu 18.04 it is highly recommended to migrate to chrony if you had set up ntpd before.

cloud-init

The version was updated to 18.2. Notable new features include:

curtin

The version was updated to 18.1. Notable features include:

MAAS

The version was updated to 2.4b2. Notable features include:

For more information, please visit the MAAS website or review the 2.4 Release Notes.

SSSD

SSSD was updated to version 1.16.x and its secrets service is now enabled. Previously it was disabled because it required the http-parser library which lived in Universe, but a successful MIR brought it to main so SSSD could link with it.

The defaults for autofs related configuration settings changed in SSSD 1.14.0 (see https://pagure.io/SSSD/sssd/issue/2858). If you are upgrading from SSSD 1.13 in Xenial, you might have to explicitly specify all ldap_autofs_* settings in your sssd.conf to match your data in LDAP.

These are the defaults, based on the setting of ldap_schema:

sssd.conf setting

xenial default

bionic default

ldap_autofs_map_object_class

automountMap

nisMap (rfc2307, autofs_provider=ad), otherwise automountMap

ldap_autofs_map_name

ou (rfc2307), automountMapName (rfc2307bis, ipa, ad)

nisMapName (rfc2307, autofs_provider=ad), otherwise automountMapName

ldap_autofs_entry_object_class

automount

nisObject (rfc2307, autofs_provider=ad), otherwise automount

ldap_autofs_entry_key

cn (rfc2307), automountKey (rfc2307bis, ipa, ad)

cn (rfc2307, autofs_provider=ad), otherwise automountKey

ldap_autofs_entry_value

automountInformation

nisMapEntry (rfc2307, autofs_provider=ad), otherwise automountInformation

Samba

The vfs module aio_linux was removed from the samba-vfs-modules package (see Debian bug #881239), and it's nowadays also no longer present in upstream Samba code. The upstream Samba bug #13128 has more details.

If you had a configuration that included this module in a share, something like this: 

[someshare]
    ...
    vfs objects = aio_linux

Then when this share is accessed, the server will notice it can't find the aio_linux module and fail. You should remove the aio_linux from the list of vfs objects that are being loaded.

Note that testparm(1) won't catch this type of error (see bug #1778860).

Nginx

nginx was updated to version 1.14.0. New features include the mirror module, HTTP/2 push, and the gRPC proxy module.

PHP

PHP was updated to version 7.2.x. For upstream guidance on migrating from PHP 7.1 (Artful's version) to 7.2: http://php.net/manual/en/migration72.php. Also of relevance might be the 7.0 to 7.1 migration documentation: http://php.net/manual/en/migration71.php.

Apache

Apache was updated to version 2.4.29. Additionally, HTTP/2 support is now enabled in 18.04.

landscape-client

landscape-client has been ported to Python 3 and is now available to install on the default image.

ubuntu-advantage-tools

s390x-specific enhancements (since 17.10)

OpenStack Queens

Ubuntu 18.04 includes the latest OpenStack release, Queens, including the following components:

Please refer to the OpenStack Queens release notes for full details of this release of OpenStack.

OpenStack Queens is also provided via the Ubuntu Cloud Archive for OpenStack Queens for Ubuntu 16.04 LTS users.

WARNING: Upgrading an OpenStack deployment is a non-trivial process and care should be taken to plan and test upgrade procedures which will be specific to each OpenStack deployment.

Make sure you read the OpenStack Charm Release Notes for more information about how to deploy Ubuntu OpenStack using Juju.

ARM64 performance considerations

Ubuntu supports 4k page size, 64K page size has benefits to certain applications and benchmarks. Please follow this link for ARM64 performance considerations that may yield similar results with 4k page size.

Known issues

As is to be expected, with any release, there are some significant known bugs that users may run into with this release of Ubuntu 18.04. The ones we know about at this point (and some of the workarounds), are documented here so you don't need to spend time reporting these bugs again:

Desktop

Server


Official flavours

The release notes for the official flavors can be found at the following links:


More information

Reporting bugs

Your comments, bug reports, patches and suggestions will help fix bugs and improve the quality of future releases. Please report bugs using the tools provided.

If you want to help out with bugs, the Bug Squad is always looking for help.

Participate in Ubuntu

If you would like to help shape Ubuntu, take a look at the list of ways you can participate at

More about Ubuntu

You can find out more about Ubuntu on the Ubuntu website and Ubuntu wiki.

To sign up for future Ubuntu development announcements, please subscribe to Ubuntu's development announcement list at:

BionicBeaver/ReleaseNotes/18.04.2 (last edited 2019-07-23 00:28:00 by gaughen)