New Features

Common Infrastructure

• Up until Ubuntu 11.10, administrator access using the sudo tool was granted via the "admin" Unix group. In Ubuntu 12.04, administrator access will be granted via the "sudo" group. This makes Ubuntu more consistent with the upstream implementation and Debian. For compatibility purposes, the "admin" group will continue to provide sudo/administrator access in 12.04.

• Hibernate (suspend to disk) has been disabled by default, as it was found to be unreliable, very slow and confusing to have two suspend modes. See bug 812394 for details. If you want to re-enable it, please follow this recipe.

• pm-utils now has two new scripts to power down USB and various PCI devices in battery mode. A number of desktop packages were fixed to wake up less often. Both of these reduce power consumption and thus improve battery lifetime.

• resolvconf is now used to manage /etc/resolv.conf on all Ubuntu systems. For systems using Network Manager DNS resolution is now done through dnsmasq, which should help split-DNS VPNs and faster DNS resolution. You can learn more here

Linux v3.2.14 Kernel

Ubuntu 12.04 ships with the 3.2.0-23.36 Ubuntu kernel which is based on the v3.2.14 upstream stable Linux kernel. Key changes since the 3.0.0-12.20 Ubuntu kernel shipped in the 11.10 Ubuntu release include:

• Rebase to upstream stable Linux kernel v3.2.14.

• The amd64 -generic and -server kernel flavors have been merged into a single -generic kernel flavor for Ubuntu 12.04. Given the few differences that existed between the two flavors, it only made sense to merge the two and reduce the overall maintenance burden over the life of this LTS release.

• The non-smp PowerPC kernel flavor has been removed.

• RC6 is enabled by default for Sandy Bridge systems. RC6 is a technology which allows the GPU to go into a very low power consumption state when the GPU is idle (down to 0W). It results in considerable power savings when this stage is activated. When comparing under idle loads with machine state where RC6 is disabled, improved power usage of around 40-60% has been witnessed.

• An improved set of jack detection patches has been backported from the upstream v3.3 Linux kernel.

• An updated AppArmor patch set has been included to better align with what is landing upstream.

• Applied and enabled the seccomp filters feature which uses the packet filtering machinery (BPF) to restrict access to system calls.

• A set of kexec fixes for arm from v3.3-rc1 has also been backported.

• We've also conducted an extensive review of Ubuntu kernel configs and made numerous config changes as a result.

Upstart 1.5

Upstart has been updated to version 1.5. More details are available in the Upstart Technical Overview.

Gnu Toolchain

Ubuntu 12.04 is distributed with a default gnu toolchain that consists of: gcc 4.6..., binutils ...., eglibc...., gdb.

Python Toolchain

Ubuntu 12.04 has ...... as the default. ? mention ongoing transition to Python 3?

Java Toolchain

The default run time for Java is OpenJDK...

Known Issues

Boot, Installation and Post-Installation

• [Dell Studio XPS 1340,Alienware m17x] Kernel panic and hang on boot due to the ite-cir driver. A patch has been sent upstream and a test kernel is referenced in the bug report. The fix will be immediately available as a kernel update from the precise-updates pocket following 12.04's release. (984387)

Upgrades

• Aptitude does not work on 64-bit systems without disabling multiarch in /etc/dpkg/dpkg.cfg.d/multiarch . (831768)

• If you have i386 packages installed on an amd64 system in Ubuntu 11.10, it is strongly recommended that you install the versions of apt and dpkg from oneiric-updates before upgrading. A number of multiarch-affecting upgrade issues have been fixed in those versions. (850264, 902603)

Kernel

• On ARM omap images, the networking support for the Beagle XM board is broken (838200)

• [Dell Studio XPS 1340,Alienware m17x] Kernel panic and hang on boot due to the ite-cir driver. A patch has been sent upstream and a test kernel is referenced in the bug report. The fix will be immediately available as a kernel update from the precise-updates pocket following 12.04's release. (984387)

• Missing support for Sentelic touchpad in Asus K53U notebook. Patches have been backported and will be immediately available as a kernel update from the precise-updates pocket following 12.04's release. (969334)

• Missing support for BCM20702A0 Broadcom bluetooth device [0489:e042]. A patch has been sent upstream. The fix will be immediately available as a kernel update from the precise-updates pocket following 12.04's release. (980965)

• Buffer overflows in comedi driver. Patches have been backported from upstream and a test kernel is referenced in the bug report. The fix will be immediately available as a kernel update from the precise-updates pocket following 12.04's release. (981234)

• Intel gma 4500mhd external monitor suffers from a scrambled picture. A patches has been backported from upstream. The fix will be immediately available as a kernel update from the precise-updates pocket following 12.04's release. (796030)

• Kernel Oops - BUG: unable to handle kernel paging request; RIP: nfs_have_delegation+0x9/0x40 [nfs]. Some users attempting to run NFS clients on 12.04 appear to be affected. A test kernel is referenced from the bug report. Patches have been backported from upstream and will be immediately available in a kernel update from the precise-updates pocket following 12.04's release. (974664)

• Patches from upstream stable v3.2.15 and v3.2.16 will undergo a baking period in the precise-proposed pocket during the first kernel SRU cycle. They will then be released as a kernel update from the precise-updates pocket approximately 3 weeks after 12.04 releases. (981162, Bug:######)

• hid-logitech-dj driver missing from the installer. It has been added to the d-i input-modules udeb and will be included in the 12.04.1 point release. (975198)

• rtl8187 driver missing from the installer. It has been added to the d-i nic-usb-modules udeb and will be included in the 12.04.1 point release. (971719)

• eGalaxis Touchscreen Driver does not work. Patches have been backported from upstream and will be immediately available in a kernel update from the precise-updates pocket following 12.04's release. (913164)

• ATI/radeon framebuffers on PowerPC only enabled as modules and not built in. This results in issues such as booting to a command prompt, loss of tty consoles, and loss of suspend. A patch to build these in have been applied and will be immediately available in a kernel update from the precise-updates pocket following 12.04's release. (949288)

Libvirt

• windows vms which previously worked with 'vga' video now need 'cirrus' video.