.. Frequently Asked Questions よくある質問 ========================== .. contents:: :local: :depth: 1 .. Why doesn't the installed system use the whole partition? インストールされたシステムがパーティション全体を使用しないのはなぜですか? --------------------------------------------------------- .. The filesystem image installed via RAUC was probably created for a size smaller than the partition on the target device. RAUC 経由でインストールされたファイル システム イメージは、ターゲット デバイスのパーティションよりも小さいサイズで作成された可能性があります。 .. Especially in cases where the same bundle will be installed on devices which use different partition sizes, tar archives are preferable to filesystem images. When RAUC installs from a tar archive, it will first create a new filesystem on the target partition, allowing use of the full size. 特に、異なるパーティション サイズを使用するデバイスに同じバンドルをインストールする場合は、ファイル システム イメージよりも tar アーカイブを使用することをお勧めします。 RAUC を tar アーカイブからインストールすると、最初にターゲット パーティションに新しいファイル システムが作成され、フル サイズを使用できるようになります。 .. Is it possible to use RAUC without D-Bus (Client/Server mode)? D-Bus (クライアント/サーバーモード) なしで RAUC を使用することはできますか? -------------------------------------------------------------- .. Yes. If you compile RAUC using the ``--disable-service`` configure option, you will be able to compile RAUC without service mode and without D-Bus support:: はい。 ``--disable-service`` 構成オプションを使用して RAUC をコンパイルすると、サービス モードおよび D-Bus サポートなしで RAUC をコンパイルできます。 ./configure --disable-service .. Then every call of the command line tool will be executed directly rather than being forwarded to the RAUC service process running on your machine. コマンド ライン ツールのすべての呼び出しは、マシンで実行されている RAUC サービス プロセスに転送されるのではなく、直接実行されます。 .. Why does RAUC not have an ext2 / ext3 file type? RAUC に ext2 / ext3 ファイルタイプがないのはなぜですか? ------------------------------------------------ .. ext4 is the successor of ext3. There is no advantage in using ext3 over ext4. ext4 は ext3 の後継です。 ext4 よりも ext3 を使用する利点はありません。 .. Some people still tend to select ext2 when they want a file system without journaling. This is not necessary, as one can turn off journaling in ext4, either during creation:: ジャーナリングなしのファイルシステムが必要な場合、依然として ext2 を選択する傾向がある人もいます。 これは必要ありません。 作成時に ext4 でジャーナリングをオフにできるためです。 mkfs.ext4 -O ^has_journal .. or later with:: またはそれ以降: tune2fs -O ^has_journal .. Note that even if there is only an ext4 slot type available, potentially each file system mountable as ext4 should work (with the filename suffix adapted). 利用可能な ext4 スロット タイプしかない場合でも、ext4 としてマウント可能な各ファイル システムが動作する可能性があることに注意してください (ファイル名の接尾辞が適用されます)。 Is the RAUC bundle format forwards/backwards compatible? -------------------------------------------------------- While RAUC now :ref:`supports ` two bundle formats (verity and crypt) in addition to the original format (plain), all are still installable by default. Support for the old format can be :ref:`disabled via the configuration `. Going forward, any issue with installing bundles using old formats or features would be considered a bug, except after an explicit deprecation period of several years. Newer RAUC versions have added features (such as casync), slot types (eMMC/MBR/GPT bootloader partitions) and bundle formats (verity and crypt). Only if you use those features by enabling them in the bundle manifest, older versions of RAUC that cannot handle them will refuse to install the bundle. As long as you don't enable new features, our intention is that bundles created by newer versions will be installable by older versions and any such issues would be considered a bug. Some background is described in the :ref:`Forward and Backward Compatibility section `. If there are ever reasons that require an incompatible change, you can use a two step migration using an :ref:`intermediate version `. Can I use RAUC with a dm-verity-protected partition? ---------------------------------------------------- Yes you can, as the offline-generated dm-verity hash tree is simply part of the image that RAUC writes to the partition. To ensure RAUC does not corrupt the partition by executing hooks or writing slot status information, use ``type=raw`` in the respective slot config and use a global (see :ref:`slot status file `) on a separate non-redundant partition with setting ``statusfile=``. Can I use RAUC with a dm-crypt-protected partition? --------------------------------------------------- Yes you can, by using the ``/dev/mapper/`` as the device for the slot (with the type of the filesystem of your choice). This way, RAUC interacts only with the unencrypted device/content. For example, with an encrypted root filesystem slot (perhaps unlocked by an initramfs loaded from a different partition): .. code-block:: cfg [slot.rootfs.0] device=/dev/mapper/crypt-rootfs0 type=ext4 bootname=system0 Remember to unlock the inactive slots as well so that RAUC can write to them. What causes a payload size that is not a multiple of 4kiB? ---------------------------------------------------------- RAUC versions up to 1.4 had an issue in the casync bundle signature generation, which caused two signatures to be appended. While the squashfs payload size is a multiple of 4kiB, the end of the first signature was not aligned. As RAUC uses the second ("outer") signature during verification, this didn't cause problems. RAUC 1.5 fixed the casync bundle generation and added stricter checks, which rejected the older bundles. In RAUC 1.5.1, this was reduced to a notification message. To avoid the message, you can recreate the bundle with RAUC 1.5 and newer. .. _faq-udev-symlinks: How can I refer to devices if the numbering is not fixed? --------------------------------------------------------- There are many reasons why device numbering might change from one kernel version to the next, across boots or even between hardware variants. In the context of RAUC, this is mainly relevant for block, MTD and UBI devices. In almost all cases, the proper way to configure this is to use `udev rules `_. For block devices, udev ships with rules which create symlinks in ``/dev/disk/by-path/``. These are not affected by changes in the probe order or by other devices that are not always connected. For example, on an emulated ARM machine, this results in:: root@qemuarm:~# ls -l /dev/disk/by-path lrwxrwxrwx 1 root root 9 Nov 18 12:46 platform-a003c00.virtio_mmio -> ../../vda By using ``/dev/disk/by-path/platform-a003c00.virtio_mmio`` in your configuration, you ensure that you always refer to the same block device. For UBI volumes, no equivalent rules are currently shipped by udev, so custom rules can be used. Depending on how the symlinks should be named, different rules could be used:: # Use the volume name instead of the number SUBSYSTEM=="ubi", KERNEL=="ubi*_*", ATTRS{mtd_num}=="*", SYMLINK+="$parent_%s{name}" # Use the MTD device number instead of the UBI device number SUBSYSTEM=="ubi", KERNEL=="ubi*_*", ATTRS{mtd_num}=="*", SYMLINK+="ubi_mtd%s{mtd_num}_%s{name}" # Use the MTD device name instead of the UBI device number SUBSYSTEM=="ubi", KERNEL=="ubi*_*", ATTRS{mtd_num}=="*", IMPORT{program}="/bin/sh -ec 'echo MTD_NAME=$(cat /sys/class/mtd/mtd%s{mtd_num}/name)'" SYMLINK+="ubi_%E{MTD_NAME}_%s{name}" When enabling all of these rules (which you should not do), you will get something like:: crw------- 1 root root 249, 0 Nov 18 13:46 /dev/ubi0 crw------- 1 root root 249, 1 Nov 18 13:46 /dev/ubi0_0 lrwxrwxrwx 1 root root 6 Nov 18 13:46 /dev/ubi0_rauc-test -> ubi0_0 lrwxrwxrwx 1 root root 6 Nov 18 13:46 /dev/ubi_nandsim_rauc-test -> ubi0_0 crw------- 1 root root 10, 59 Nov 18 13:46 /dev/ubi_ctrl lrwxrwxrwx 1 root root 6 Nov 18 13:46 /dev/ubi_mtd3_rauc-test -> ubi0_0 Custom udev rules can also be very useful when you want to refer to the active data partition (in a scenario with redundant data partitions) with a fixed name.