Catatan rilis ini mendokumentasikan masalah yang telah diketahui pada Ubuntu 10.04 LTS dan variannya.

Kebutuhan Sistem

Kebutuhan memori minimal untuk Ubuntu 10.04 LTS adalah 256 MB. Perhatikan bahwa sebagian dari memori sistem Anda mungkin tidak tersedia karena sedang digunakan oleh kartu grafis. Jika komputer Anda hanya memiliki jumlah minimal memori, proses instalasi akan memakan waktu lebih lama dari biasanya, tapi akan selesai dengan sukses, dan sistem akan berjalan cukup baik setelah diinstal.

Sistem dengan memori kurang mungkin dapat memilih "Install Ubuntu" dari menu boot hanya untuk menjalankan installer, bukan seluruh desktop, atau mungkin dapat menggunakan CD alternate install.

Catatan rilis bagi Ubuntu 10.04 untuk ARM

Sebuah halaman terpisah telah tersedia dengan catatan rilis untuk Ubuntu 10.04 port armel yang berorientasi-pengembang. Silakan lihat https://wiki.ubuntu.com/ARM/LucidReleaseNotes untuk informasi tentang isu-isu yang berdampak atas instalasi pada ARM.

Instalasi

Kinerja memburuk dengan ext4 dengan beban kerja tertentu

Sistem berkas baku untuk instalasi Ubuntu 10.04 LTS adalah ext4, versi terbaru di seri populer dari sistem berkas extended Linux. ext4 menyertakan sejumlah perubahan penalaan kinerja relatif terhadap versi sebelumnya seperti ext3, sistem berkas yang digunakan secara baku sampai dengan Ubuntu 9,04. Ini umumnya menghasilkan perbaikan, tetapi beberapa beban kerja tertentu diketahui secara signifikan lebih lambat ketika menggunakan ext4 daripada ketika menggunakan ext3. Jika Anda memiliki aplikasi yang peka kinerja, kami menyarankan Anda menjalankan benchmark menggunakan beberapa sistem berkas di lingkungan Anda dan pilih paling tepat.

Secara khusus, manajer paket dpkg telah diketahui berjalan lebih lambat secara signifikan pada ext4, menyebabkan instalasi menggunakan CD instalasi server atau alternatif memerlukan waktu dua kali lebih lama daripada sebelumnya. ext4 tidak menjamin perubahan nama secara atomik berkas baru atas berkas yang telah ada ketika sejenak setelah mengubah nama, listrik terputus, sehingga dpkg perlu memaksa isi dari file baru ke disk sebelum mengganti nama itu agar terhindar dari meninggalkan berkas dengan panjang nol setelah gangguan listrik. Operasi ini melibatkan menunggu disk yang secara signifikan lebih lama daripada yang benar-benar diperlukan, sehingga menurunkan kinerja. Jika operasi manajemen paket yang cepat paling penting bagi Anda, maka Anda harus menggunakan ext3 sebagai gantinya. (570805)

Cara termudah untuk memilih sistem berkas yang berbeda seperti ext3 pada waktu instalasi adalah dengan menambahkan parameter boot partman/default_filesystem=ext3 saat menjalankan installer. Jika Anda memasang Ubuntu secara otomatis menggunakan Kickstart atau pra pembibitan, maka Anda dapat mengatur sistem berkas yang berbeda dalam resep pemartisian.

Paket yang disarankan dipasang secara default

Sesuai dengan Debian Policy Manual (yang menyatakan "ruas 'merekomendasikan' harus mendaftar paket yang akan ditemukan bersama dengan yang satu ini di semua instalasi kecuali yang tak biasa"), sistem manajemen paket sekarang menginstal paket-paket yang tercantum dalam ruas Recommends: dari paket terpasang lainnya beserta Depends: secara default. Jika Anda ingin menghindari ini untuk paket tertentu, gunakan apt-get -no-install-recommends, jika Anda ingin membuat ini permanen, set APT:: Install-Recommends "false"; dalam /etc/apt/apt.conf. Perlu diketahui bahwa hal ini dapat mengakibatkan hilangnya fitur dalam beberapa program.

(Perubahan ini dibuat di Ubuntu 8.10.)

Hibernasi mungkin tak tersedia dengan pemartisian otomatis

Resep pemartisian baku pada installer pada beberapa kasus akan mengalokasikan partisi swap yang kurang dari memori fisik pada sistem. Ini akan mencegah pemakaian hibernasi (suspend-to-disk) karena image sistem tidak akan muat di partisi swap. Bila Anda ingin memakai hibernasi dengan sistem Anda, pastikanlah bahwa ukuran partisi swap paling tidak sebesar RAM fisik sistem. (345126)

I/O error after CD is ejected at end of install

In some cases, ejecting the CD at the end of installation will leave errors on the screen such as:

end_request: I/O error, dev sr0, sector 437628

these error messages indicate that the system is still trying to access some files on the CD, and are harmless except that they obscure the message asking the user to press Enter to reboot. You can safely remove the CD from the tray and press Enter at this point to reboot to your new Ubuntu system. (539027)

Boot options hidden by default on Desktop and Netbook CDs

The Ubuntu 10.04 LTS Desktop and Netbook CDs feature a new boot interface that is noninteractive by default. To configure advanced boot options, press any key at the first boot screen.

Installer crash with a separate /home partition

A bug in migration-assistant prevents some users with separate home partitions from completing the install successfully. Users who experience such a crash can disable migration-assistant by selecting "Try Ubuntu" at the first screen of the installer, then pressing Alt-F2 and typing ubiquity --no-migration-assistant at the prompt that appears. (536673)

Dmraid active by default on Desktop CD

Dmraid "fake raid" devices are supported out-of-the-box on the Ubuntu 10.04 LTS Desktop CD, and are detected and activated by dmraid on boot. Ubiquity will offer to install on the RAID array, and not on the RAID members.

The automatic activation of dmraid can be disabled with the "nodmraid" boot option, available by pressing F6 in the CD boot menu. This can be useful for setups which have fakeraid metadata present on the disks, but where dmraid activation would be undesired or cause problems.

Partition alignment changes may break some systems

By default, Ubuntu 10.04 LTS aligns partitions on disk to 1 MiB (1048576 bytes) boundaries. This ensures maximum performance on many modern disks, particularly solid state drives but also new "Advanced Format" disks with physical sectors larger than the traditional 512 bytes. Very few systems nowadays need the old alignment, used in the days of MS-DOS when it was useful for partitions to start at the beginning of a cylinder.

In some rare cases, optimal alignment may cause problems. Some BIOS implementations (those on Asus P5P800-MX and Asus P5GZ-MX motherboards) have been reported to hang after installation. It may be difficult to install Microsoft Windows XP and older after installing Ubuntu, although more recent versions of Windows should be compatible with optimal alignment and indeed may produce it themselves. If you find that you need to use the old cylinder alignment instead, then add the partman/alignment=cylinder boot parameter when starting the installer. (551965)

Desktop installer sometimes crashes on startup

On some machines, the CD boot fails with the message "The installer encountered an unrecoverable error. A desktop session will now be run so that you may investigate the problem or try installing again." If you encounter this error, restart your computer with the CD inserted, press any key at the splash screen (when you see the keyboard icon at the bottom of the screen), and select "Try Ubuntu without installing". Once the desktop appears, use the "Install Ubuntu 10.04" icon to begin installing Ubuntu. (567899)

Upgrading

Users of Ubuntu 9.10 and Ubuntu 8.04 LTS can upgrade to Ubuntu 10.04 by a convenient automated process. Users of other Ubuntu releases need to upgrade first to either Ubuntu 8.04 LTS or Ubuntu 9.10, and then to 10.04. Complete instructions may be found at http://www.ubuntu.com/getubuntu/upgrading.

GRUB menu.lst: install the maintainer's version vs. keep the local version

If you have previously modified the menu.lst bootloader configuration for GRUB, either by hand or with a tool such as kgrubeditor, you may be asked on upgrade whether you wish to keep your local version of the menu.lst or install the package maintainer's version. This question is asked because such changes cannot be merged automatically with 100% reliability, and care is taken to not overwrite the user's manually edited bootloader configuration without warning.

However, if you choose to "keep the local version currently installed," your system will not be set up to boot from any newly-installed kernels. Manual action is required on your part to ensure that your system is running the current, security-supported kernel after upgrade. If you have local changes to your bootloader config that you want to keep, it is recommended that you follow these steps:

• Choose "keep the local version currently installed" at the prompt.

• Open /boot/grub/menu.lst with a text editor (e.g., sudo gedit /boot/grub/menu.lst).

• Apply any changes you've made to the kernel boot options to the commented variables (e.g., groot, kopt, defoptions) above.

• Move any manually-added boot options for other operating systems so that they are above the line

  ### BEGIN AUTOMAGIC KERNELS LIST

  or below the line

  ### END DEBIAN AUTOMAGIC KERNELS LIST

• Save the file, and run sudo update-grub from the commandline.

• Choose "install the package maintainer's version".

For example, if you added an option i915.modeset=0 to the "kernel" line:

kernel          /vmlinuz-2.6.31-14-generic root=UUID=0e7... ro quiet splash i915.modeset=0

then add this option to kopt:

# kopt=root=UUID=0e7... ro i915.modeset=0

An updated version of the grub package will include information about this problem in the help screen for the menu.lst prompt. (470490)

Setting wireless regulatory domain via module option no longer supported

Ubuntu 10.04 LTS 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.conf 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 9.10 and use the iw reg command instead.

(This change was made in Ubuntu 9.04.)

Bonded network interfaces must use hotplug-style configuration

The migration of network handling to upstart means that all network devices are now handled in a hotplug manner. As a result, bonded interfaces are only brought up reliably on boot when the bonded interface is created as part of the configuration of the physical interface; otherwise, the system may attempt to bring up the bonded interface before the underlying physical interfaces are available, and fail. For an example of how to configure a bonding interface for hotplug, please see /usr/share/doc/ifenslave-2.6/examples/two_hotplug_ethernet in the ifenslave-2.6 package.

(This change was made in Ubuntu 9.10.)

Kubuntu may keep unneeded guidance power package

The kubuntu upgrade may leave the no longer needed packages "kde-guidance-powermanager" or "guidance-power-manager" installed. Those can be removed.

Ctrl-Alt-Backspace disabled by default in Xorg, configured via XKB

Since Ubuntu 9.04, 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. In addition, the Ctrl-Alt-Backspace option is now configured as an X keymap (XKB) option, replacing the X server "DontZap" option and allowing per-user configuration of this setting.

As a result, enabling or disabling the Ctrl+Alt+Backspace shortcut can now be done easily from the desktop.

Enabling Ctrl-Alt-Backspace for Ubuntu

• Select "System"->"Preferences"->"Keyboard"

• Select the "Layouts" tab and click on the "Layout Options" button.
• Select "Key sequence to kill the X server" and enable "Control + Alt + Backspace".

Enabling Ctrl-Alt-Backspace for Kubuntu

• Click on the Application launcher and select "System Settings"

• Click on "Regional & Language".

• Select "Keyboard Layout".
• Click on "Enable keyboard layouts" (in the Layout tab).
• Select the "Advanced" tab. Then select "Key sequence to kill the X server" and enable "Control + Alt + Backspace".

For further information, see: https://wiki.ubuntu.com/X/Config/DontZap

Change in notifications of available updates

Ubuntu 10.04 LTS launches update-manager directly to handle package updates, instead of displaying a notification icon in the GNOME panel. Users are 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

(This change was made in Ubuntu 9.04.)

MySQL upgrade

In Ubuntu 10.04 LTS, MySQL 5.1 has been promoted as the default MySQL server. MySQL 5.0 is still available from the universe repository. Performing an upgrade via update-manager will correctly handle the transition from MySQL 5.0 to MySQL 5.1. However using a dist-upgrade will not: mysql-server-5.0 will be upgraded instead of being replaced by mysql-server-5.1. If MySQL 5.0 needs to be kept the mysql-server and mysql-client packages should be removed before the upgrade is started.

(This change was made in Ubuntu 9.10.)

MySQL Cluster setup

If MySQL has been set up to use the MySQL Cluster engine (NDB engine), upgrading to MySQL 5.1 will not work since the mysql-dfsg-5.1 packages don't support MySQL Cluster. Instead mysql-server and mysql-client should be removed before upgrade and mysql-server-5.0 should be kept. update-manager will automatically take care of this situation. Note that MySQL 5.0 is in universe and thus won't have have the same maintenance coverage as the MySQL 5.1 package in main.

/etc/event.d no longer used

The version of upstart included in Ubuntu 10.04 LTS no longer uses the configuration files in the /etc/event.d directory, looking to /etc/init instead. No automatic migration of changes to /etc/event.d is possible. If you have modified any settings in this directory, you will need to reapply them to /etc/init in the new configuration format by hand. (402759)

(This change was made in Ubuntu 9.10.)

Syslog upgrade

The sysklogd package has been replaced with rsyslog. Configurations in /etc/syslog.conf will be automatically migrated to /etc/rsyslog.d/50-default. If you modified the log rotation settings in /etc/cron.daily/sysklogd or /etc/cron.weekly/sysklogd, you will need to change the new configurations in /etc/logrotate.d/rsyslog. Also note that the prior rotation configurations used .0 as the first rotated file extension, and now with logrotate it will be .1.

(This change was made in Ubuntu 9.10.)

LPIA architecture discontinued

The lpia architecture present in previous releases has been discontinued as of Ubuntu 10.04 LTS. The hardware is still supported, but systems that were installed as lpia will need to be backed up and reinstalled from scratch using either the i386 or amd64 architectures. See bug 523295, which includes an unsupported method for migration from lpia to i386.

Dovecot cmusieve plugin renamed to sieve

The "cmusieve" plugin used in dovecot has been renamed to "sieve". Users who have the following set in their dovecot configuration:

        mail_plugins = cmusieve

should change this to:

        mail_plugins = sieve

Other known issues

Security Issue when upgrading from Lucid Alpha 2

If you installed Lucid prior to Alpha 3, you may have libmysqlclient16 7.0.9-1 installed. This package was present in the Ubuntu archive by mistake and was retracted, but because it has a later version number than the real libmysqlclient16 package, the real package will not be installed automatically on upgrade. To ensure that you have the official package installed on your Lucid system and will receive security support for it throughout Ubuntu 10.04 LTS, it is important that you run sudo apt-get install libmysqlclient16/lucid and follow the instructions. (522225)

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 10.04 LTS 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.

Upstart jobs cannot be run in a chroot

Upstart jobs cannot be started in a chroot because upstart acts as a service supervisor, and processes within the chroot are unable to communicate with the upstart running outside of the chroot (430224). This will cause some packages that have been converted to use upstart jobs instead of init scripts to fail to upgrade within a chroot. Users are advised to configure their chroots with /sbin/initctl pointing to /bin/true, with the following commands run within the chroot:

dpkg-divert --local --rename --add /sbin/initctl
ln -s /bin/true /sbin/initctl

Encrypted partitions must be listed in /etc/fstab

Users who have configured any encrypted partitions in /etc/crypttab to start at boot time (i.e., not using the noauto option) should make sure that the filesystems on these volumes are listed in /etc/fstab. Otherwise, the passphrase prompt is not guaranteed to be displayed at boot time.

Avahi will always start even if a .local domain is present

The avahi-daemon package, which implements the mDNS "zeroconf" standard, formerly included a check to avoid running when a conflicting .local DNS domain is present, as it was reported that some ISPs advertise such a .local domain on their networks, leaving Ubuntu hosts unable to see names advertised on the local network (327362). In Ubuntu 9.10, avahi-daemon is started regardless.

It is possible that this may cause other problems. If your network is configured this way, you can disable mDNS using the following command:

sudo stop avahi-daemon
sudo sed -e '/^start/,+1s/^/#/' /etc/init/avahi-daemon.conf

Working around bugs in the new kernel video architecture

Ubuntu 10.04 LTS enables the new kernel-mode-setting (KMS) technology by default on most common video chipsets. While this is a major step forward for the graphics architecture in Ubuntu, in some rare cases KMS will prevent your video output from working correctly, or from working at all. If you need to disable KMS, you can do so by booting with the nomodeset option. You can also save this setting so that it's applied at every boot by adding it to your grub config (for GRUB 2: edit /etc/default/grub and add nomodeset to GRUB_CMDLINE_LINUX, then run sudo update-grub; for GRUB 1: edit /boot/grub/menu.lst and add nomodeset to the line beginning with # kopt=, then run sudo update-grub). (533784, 541501)

Evince PDF viewer does not work for nonstandard home directories

Evince, the GNOME document viewer, now ships with an enforcing AppArmor profile. This greatly increases security by protecting users against flaws in the historically problematic PDF and image libraries. Users who use a non-standard location for their home directory will need to adjust the home tunable in /etc/apparmor.d/tunables/home. See https://wiki.ubuntu.com/DebuggingApparmor#Adjusting%20Tunables for details.

No delay for boot menu with GRUB 2

When using the GRUB 2 bootloader included in Ubuntu 10.04 LTS, the first boot option will by default be loaded automatically without pausing for user input. To interrupt the boot, users can hold down the Shift key to bring up the boot menu, allowing them to select a different boot option or to configure kernel arguments. (https://help.ubuntu.com/community/Grub2#GRUB%20vs%20GRUB%202)

Sun Java moved to the Partner repository

For Ubuntu 10.04 LTS, the sun-java6 packages have been dropped from the Multiverse section of the Ubuntu archive. It is recommended that you use openjdk-6 instead.

If you can not switch from the proprietary Sun JDK/JRE to OpenJDK, you can install sun-java6 packages from the Canonical Partner Repository. You can configure your system to use this repository via command-line:

     add-apt-repository "deb http://archive.canonical.com/ lucid partner"

Window corruption with older ATI graphics cards

With older ATI graphics cards with 32MB or less of video RAM some corruption of direct rendered windows, for example OSD notifier windows, might appear. This may be worked around by disabling 'RenderAccel' in the Xorg configuration. (426582)

To do this first exit to the console using the following command:

• sudo service gdm stop

Then create an Xorg configuration file with the command below:

• sudo Xorg -configure

Then add the 'RenderAccel' option to /etc/X11/xorg.conf:

• Section "Device"
          ...
          Driver "radeon"
          Option "RenderAccel" "off"
  EndSection

And restart X/GDM.

• sudo service gdm start

Incompatibility with nVidia upstream driver installer

Ubuntu 10.04 LTS includes improved integration for nVidia binary driver packages. Unfortunately, this comes at the expense of compatibility with the installer provided upstream on the nVidia website. Users who wish to use the nVidia binary video drivers with 10.04 LTS should install them using the Ubuntu packages, as made available under System -> Administration -> Hardware Drivers.

Intel 8xx X freezes/crashes

The -intel driver fails with X freezes or crashes on certain i8xx hardware. The issue is known upstream but solutions are still under development. For now, to work around the issue, boot with the -vesa video driver. See http://wiki.ubuntu.com/X/Lucidi8xxFreezes for further details.