ReleaseNotes

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== Network Management Applet Needs Added on Upgrade == == Network management applet must be re-added on Kubuntu upgrade ==
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When upgrading from Kubuntu 8.10 the Network Management applet will need added to the panel manually. (bug Bug:349066) When upgrading from Kubuntu 8.10, the new Network Management applet will need to be added to the panel manually. (Bug Bug:349066)
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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

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.

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).

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 alphas may need re-encryption of encrypted home directories

Users who were running eCryptfs on the Jaunty Alpha milestones are advised to re-encrypt any encrypted files. An upstream 2.6.28 kernel bug caused random kernel memory to be written to eCryptfs encrypted file headers. The fix has been applied and deployed to Ubuntu users in the Jaunty RC kernel. Ubuntu eCryptfs users running this kernel should re-encrypt each encrypted file using /usr/bin/ecryptfs-rewrite-file. For more information, please see ecryptfs-rewrite-file(1). See 345544.

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

Setting wireless regulatory domain via module option no longer supported

Ubuntu 9.04 enables the CRDA wireless regulatory framework for controlling which wireless channels are usable and visible in a particular location. If you previously had to use the module option similar to that below in /etc/modprobe.d/options to allow access to certain channels in your locality then you may find that wireless will not function at all:

  • options cfg80211 ieee80211_regdom=EU

You should remove this kernel module option on upgrade to Ubuntu 9.04 and use the iw reg command instead.

Network management applet must be re-added on Kubuntu upgrade

When upgrading from Kubuntu 8.10, the new Network Management applet will need to be added to the panel manually. (Bug 349066)

plasma-1.png

plasma-2.png

plasma-3.png

Click the Plama icon in the bottom right.

Click Add Widget.

Double click on Network Management.

Ctrl-Alt-Backspace disabled by default in Xorg

The Ctrl-Alt-Backspace key combination to force a restart of X is now disabled b default, to eliminate the problem of accidentally triggering the key combination. Users who do want this function can enable it in their xorg.conf, or by running the command dontzap --disable.

Other known issues

Performance regressions on Intel graphics cards

Users of Intel video chipsets have reported performance regressions in Ubuntu 8.10 compared with previous releases (bug 252094). Many of the issues have been resolved in Ubuntu 9.04, but some remain.

  • Some users have found improved performance by using the "greedy" migration heuristic. This can be done by running "sudo gedit /etc/X11/xorg.conf", and adding Option "MigrationHeuristic" "greedy" to the Device section of your xorg.conf.

  • Alternately, a new experimental acceleration architecture option, "DRI2/UXA", is available for Intel graphics users which our testing has found provides significant performance improvements in some cases, but has also shown risk of severe stability problems. You can opt-in to enable this by running "sudo gedit /etc/X11/xorg.conf", and adding Option "AccelMethod" "UXA" to the Device section of your xorg.conf. Users wishing to maximize stability should stay with the standard default acceleration method, "EXA".

  • If none of the above helps, some users reported success with using an older driver version.

Suspend/Hibernate hangs with Intel graphics cards

Users of Intel video chipsets reported that the display freezes a few minutes after resuming from suspend or hibernate (bug 339091). As a workaround you can add Option "DRI" "off" to the Device section of /etc/X11/xorg.conf, as described above. This will disable 3D acceleration and desktop effects, but makes suspend work reliably again.

Lock-ups when deleting files from ext4 filesystems

In some cases, deleting files from an ext4 filesystem is reported to cause soft lock-ups in the kernel (330824). Investigation of this problem is ongoing, and it is expected that a fix for this problem will be made available as a post-release update. To avoid this problem, users may wish to install using the default ext3 filesystem and convert their filesystem to ext4 (as documented on the ext4 wiki) once a fix is available.

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.

JauntyJackalope/ReleaseNotes (last edited 2009-12-23 00:53:13 by ip72-213-131-215)