These release notes document known issues with Ubuntu 9.04 and its variants.

System Requirements

The minimum memory requirement for Ubuntu 9.04 is 256 MiB of memory. (Note that some of your system's memory may be unavailable due to being used by the graphics card.)

With only the minimum amount of memory available, the installation process will take longer than normal, but will complete successfully, and the system will perform adequately once installed. Low-memory systems may be able to use the desktop CD to install by selecting "Install Ubuntu" from the boot menu to run just the installer, rather than the whole desktop started by selecting "Try Ubuntu without any change to your computer".

Installation

Recommended packages installed by default

In accordance with the Debian Policy Manual (which says "The 'Recommends' field should list packages that would be found together with this one in all but unusual installations"), the package management system now installs packages listed in the Recommends: field of other installed packages as well as Depends: by default. If you want to avoid this for specific packages, use apt-get --no-install-recommends; if you want to make this permanent, set APT::Install-Recommends "false"; in /etc/apt/apt.conf. Be aware that this may result in missing features in some programs.

(This change was made in Ubuntu 8.10.)

Upgrading

Users of Ubuntu 8.10 can upgrade to Ubuntu 9.04 by a convenient automated process. Users of older Ubuntu releases need to upgrade to Ubuntu 8.10 first, and then to 9.04. Complete instructions may be found at http://www.ubuntu.com/getubuntu/upgrading.

Kubuntu users can upgrade directly from Kubuntu 8.04 to Kubuntu 9.04. Users upgrading in this way are advised to also read the release notes for Ubuntu 8.10, as the issues described there will also apply.

nVidia "legacy" video support

The 71 and 96 series of proprietary nVidia drivers, as provided by the nvidia-glx-legacy and nvidia-glx packages in Ubuntu 8.04 LTS, are not compatible with the X.Org included in Ubuntu 9.04. Users with the nVidia TNT, TNT2, TNT Ultra, GeForce, GeForce2, GeForce3, and GeForce4 chipsets are affected and will be transitioned on upgrade to the free nv driver instead. This driver does not support 3D acceleration.

Users of other nVidia chipsets that are supported by the 173 or 177 driver series will be transitioned to the nvidia-glx-173 or nvidia-glx-177 package instead. However, unlike drivers 96 and 71, drivers 173 and 177 are only compatible with CPUs that support SSE (e.g. Intel Pentium III, AMD Athlon XP or higher). Systems with older CPUs will also be transitioned to the nv driver on upgrade.

ATI "fglrx" video support

The ATI video driver in 9.04 drops support for video cards with r300 based chips (the Radeon 9500 - X600 Series of cards). If you have such a card, please use "Hardware Drivers" at System/Administration to disable it before the upgrade. Please see bug 284408 for more information.

X.Org Input Devices

The X.Org configuration file (/etc/X11/xorg.conf) still has InputDevice entries for the mouse and keyboard, but they are ignored now because input-hotplug is used. The keyboard settings now come from /etc/default/console-setup; to change them please use sudo dpkg-reconfigure console-setup. After that, HAL and X need to be restarted (e.g., by rebooting your system).

(This change was made in Ubuntu 8.10.)

X.Org evdev xmodmap incompatibility

The X keycodes generated with the new evdev input driver in X.Org 1.5 are not compatible with those generated in Ubuntu 8.04 LTS and before. If you have configured keybindings for your user with a ~/.Xmodmap file, you will need to convert or disable it by hand on upgrade.

(This change was made in Ubuntu 8.10.)

Boot failures on systems with Intel D945 motherboards

Users have reported slower than normal detection of SATA hard drives on systems with Intel D945 motherboards in Ubuntu 9.04. This may cause the system to drop to a busybox initramfs shell on boot with a "Gave up waiting for root device." error. Wait a minute or two and then exit the initramfs shell by typing 'exit'. Booting should proceed normally. If it doesn't, wait a bit longer and try again. Once the system boots, edit /boot/grub/menu.lst and add rootdelay=90 to the kernel stanza for your current kernel. (Bug 290153).

Support for ssl/blowfish-v0.2, version 2:0:1 not in encfs

Compatibility for this old algorithm was dropped in the 1.4.x version of encfs included in Ubuntu 9.04. Before upgrading, users of this algorithm will have to manually migrate their encfs volumes to a new one created with the new version. Alternatively, you may stay at an old version of encfs to be able to read the volumes.

(This change was made in Ubuntu 8.10.)

Upgrades from beta may use LABEL= in /etc/fstab

Systems installed using Jaunty Alpha 5, Jaunty Alpha 6, or the Ubuntu 9.04 beta may use LABEL= syntax in /etc/fstab to identify file systems. This may cause unexpected behaviour later if another disk (such as a USB drive) is added later containing file systems with clashing labels. Unless you are sure that this is what you intend, we recommend that you switch to using universally unique identifiers (UUIDs) instead.

For example, if a file system is identified as LABEL=home in /etc/fstab, you can find the UUID as follows:

blkid -o value -s UUID -l -t LABEL=home

You can then replace LABEL=home with UUID=output, where output is the output of blkid.

Systems installed using the release candidate or final release of Ubuntu 9.04 do not have this problem.

Upgrades from Ubuntu 8.10 may have lilo installed

Ubuntu 8.10 systems installed from the desktop CD mistakenly had the lilo package installed as well as grub, although grub was used for booting. If you use the recommended Update Manager upgrade method, then the lilo package will be removed if it does not appear to be used. If you upgrade using some other method and are sure that you only use the GRUB boot loader, then we recommend that you remove the lilo package manually. Bug 314004

Other known issues

Switching to ext4 requires manually updating grub

If you choose to upgrade your / or /boot filesystem in place from ext2 or ext3 to ext4 (as documented on the ext4 wiki), then you must also use the grub-install command after upgrading to Ubuntu 9.04 to reinstall your boot loader. If you do not do this, then the version of GRUB installed in your boot sector will not be able to read the kernel from the ext4 filesystem and your system will fail to boot.

Occasional hangs possible on ARM architecture

The ARM port currently does not support the ppoll() & pselect() system syscalls, which will sometimes cause a failure to mount the root filesystem on boot. This is a race condition, and retrying the boot will usually clear the problem. The work to add the syscalls is currently underway and will be delivered as an update to the Ubuntu 9.04 kernel some time after release.