ReleaseNotes

Differences between revisions 42 and 43
Revision 42 as of 2009-04-21 13:15:11
Size: 11601
Editor: 82
Comment: Fixed typo and shortened sentence
Revision 43 as of 2009-04-21 13:39:49
Size: 11805
Editor: minbar
Comment: errata for bug #359338
Deletions are marked like this. Additions are marked like this.
Line 66: Line 66:
Some users have been able to use packages by Per Hermansson (mentioned in [[Bug:334052|Bug 334052]]) while others have had success installing the "linux-backports-modules-jaunty-generic"-package (ref:[[Bug:348275|Bug 348275]]) to get WPA2-support.
Line 112: Line 110:
== Apparmor profiles incompatible with ecryptfs ==

When using encrypted home directories together with apparmor in enforcing mode, apparmor will deny access to certain files unexpectedly because the Linux kernel sees the process as accessing the file via both the unencrypted and encrypted paths (Bug:359338). As a workaround, users can modify their apparmor profiles under {{{/etc/apparmor.d/}}} to grant permissions to {{{@{HOME}/.Private/**}}}.


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 MB of memory. Note that some of your system's memory may be unavailable due to being used by the graphics card. If your computer has only the minimum amount of memory, the installation process will take longer than normal, but will complete successfully, and the system will perform adequately once installed.

Systems with less memory may be able to select "Install Ubuntu" from the boot menu to run just the installer, rather than the whole desktop.

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 Bug 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 Plasma icon in the bottom right.

Click Add Widget.

Double click on Network Management.

Kubuntu Network Management applet does not connect to WPA2 networks

The Network Management applet in Kubuntu does not connect to WPA 2 network or some VPN setups. You can use knetworkmanager (available on the DVD) or network-manager-gnome as a workaround. Bug 339313

Ctrl-Alt-Backspace disabled by default in Xorg

The Ctrl-Alt-Backspace key combination to force a restart of X is now disabled by 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.

Change in notifications of available updates

Ubuntu 9.04 introduces a change to the handling of package updates, launching update-manager directly instead of displaying a notification icon in the GNOME panel. Users will still be notified of security updates on a daily basis, but for updates that are not security-related, users will only be prompted once a week.

Users who wish to continue receiving update notifications in the previous manner can restore the earlier behavior using the following command:

gconftool -s --type bool /apps/update-notifier/auto_launch false

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.

  • Alternatively, 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".

    Warning /!\ In some cases this will lead to the graphical environment not starting at all or becoming entirely unusable. In that case, start into rescue mode or press Ctrl+Alt+F2 and log into the text console, and use sudo nano /etc/X11/xorg.conf to revert the UXA option.

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

Display freezes with Intel graphics cards

Users of various Intel video chipsets reported freezes under various conditions (e. g. a few minutes after suspend on the i945, see bug 339091). In many cases, switching off desktop effects in System → Preferences → Appearance was reported to help.

If it still happens without desktop effects, 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 and also avoid many types of crashes.

These freezes happen particularly often on the i965 chips (bug 359392). For that reason, desktop effects were disabled by default on this chipset in the final release. They will be re-enabled in a 9.04 Update once the problem has been fixed.

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.

Apparmor profiles incompatible with ecryptfs

When using encrypted home directories together with apparmor in enforcing mode, apparmor will deny access to certain files unexpectedly because the Linux kernel sees the process as accessing the file via both the unencrypted and encrypted paths (359338). As a workaround, users can modify their apparmor profiles under /etc/apparmor.d/ to grant permissions to @{HOME}/.Private/**.

Wubi reuses a pre-existing "ubuntu" directory and removes it upon uninstallation

If there is a pre-existing directory called "ubuntu" in the target drive, it will be reused during the Windows installation, and the full directory will be removed upon uninstallation (364166). This will result in the loss of the files which were originally in that directory. It is recommended to rename any directory called "ubuntu" before proceeding with a Wubi installation.

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)