[Kernel-packages] [Bug 2044104] [NEW] [UBUNTU 20.04] chzdev -e is rebuilding initramfs even with zdev:early=0 set
Public bug reported: Versions: Ubuntu 20.04.5 s390-tools version 2.12.0-0ubuntu3.7.s390x Ubuntu 22.04.2 s390-tools version 2.20.0-0ubuntu3.2.s390x When I configure a zfcp LUN persistently via chzdev, the initrd is being rebuilt even with parameter zdev:early=0 root@a8315003:~# chzdev -e zfcp-lun 0.0.1803:0x500507630910d430:0x40194092 zdev:early=0 zFCP LUN 0.0.1803:0x500507630910d430:0x40194092 configured Note: The initial RAM-disk must be updated for these changes to take effect: - zFCP LUN 0.0.1803:0x500507630910d430:0x40194092 update-initramfs: Generating /boot/initrd.img-5.15.0-60-generic I: The initramfs will attempt to resume from /dev/dasdb1 I: (UUID=e70ecb80-4d1e-4074-9cda-ce231ad6e698) I: Set the RESUME variable to override this. Using config file '/etc/zipl.conf' Building bootmap in '/boot' Adding IPL section 'ubuntu' (default) Preparing boot device: dasda (c00a). Done. root@a8315003:~# == Comment: - Thorsten Diehl - 2023-03-01 06:55:47 == @BOE-dev This behaviour is unexpected. https://www.ibm.com/docs/en/linux-on-systems?topic=commands-chzdev says: Activating a device early during the boot process Use the zdev:early device attribute to activate a device early during the boot process and to override any existing auto-configuration with a persistent device configuration. zdev:early=1 The device is activated during the initial RAM disc phase according to the persistent configuration. zdev:early=0 The device is activated as usual during the boot process. This is the default. If auto-configuration data is present, the device is activated during the initial RAM disc phase according to the auto-configuration. I can't interprete a SCSI LUN as a device with auto configuration data. (At least, if the zfcp device hasn't NPIV enabled) == Comment: #5 - Peter Oberparleiter - 2023-03-01 11:18:28 == (In reply to comment #2) > @BOE-dev > This behaviour is unexpected. > https://www.ibm.com/docs/en/linux-on-systems?topic=commands-chzdev says: > Activating a device early during the boot process > > Use the zdev:early device attribute to activate a device early during the > boot process and to override any existing auto-configuration with a > persistent device configuration. > > zdev:early=1 > The device is activated during the initial RAM disc phase according to > the persistent configuration. > > zdev:early=0 > The device is activated as usual during the boot process. This is the > default. If auto-configuration data is present, the device is activated > during the initial RAM disc phase according to the auto-configuration. The documentation is incorrect for Ubuntu. Canonical specifically builds zdev in a way that every change to persistent device configuration causes an update to the initial RAM-disk. See also: https://bugzilla.linux.ibm.com/show_bug.cgi?id=187578#c35 https://github.com/ibm-s390-linux/s390-tools/commit/7dd03eaeecdd0e2674f145aca34be1275d291bd8 > I can't interprete a SCSI LUN as a device with auto configuration data. (At > least, if the zfcp device hasn't NPIV enabled) This is related to auto-configuration as implemented for DPM. == Comment: #6 - Thorsten Diehl - 2023-03-03 12:41:44 == So, IIUC, chzdev is built for Ubuntu with ZDEV_ALWAYS_UPDATE_INITRD=1, which make the parameter zdev:early=0 ineffective. Correct? If you confirm, you may also close this bug. Not nice - then we have to find an alternate solution. == Comment: #7 - Peter Oberparleiter - 2023-03-07 06:48:07 == (In reply to comment #6) > So, IIUC, chzdev is built for Ubuntu with ZDEV_ALWAYS_UPDATE_INITRD=1, which > make the parameter zdev:early=0 ineffective. Correct? > If you confirm, you may also close this bug. > > Not nice - then we have to find an alternate solution. chzdev -p on Ubuntu will by default rebuild the initrd. This is intended behavior by Canonical and controlled by the ZDEV_ALWAYS_UPDATE_INITRD build-time switch. You can suppress it by adding option --no-root-update to the command line. Specifying zdev:early=0 to chzdev has exactly the effect that it is supposed to have: it tells zdev not to enable that device during initrd processing, resulting in the corresponding udev rule not being copied to the initrd [1]. Unfortunately there is another Ubuntu-initrd script [2] that simply copies ALL udev rules, including those created by zdev, into the initrd. As a result, zdev's early-attribute handling is rendered useless and all devices are enabled, even if a user specified zdev:early=0. Since this bug report indicates that there is a use-case for this function in Ubuntu, it might be worth asking Canonical if current processing could be changed to provide a way for users to specify that a device should specifically NOT be enabled within initrd processing. Technically this could easily be done: 1) Have the generic udev initramfs script not copy zdev-generated Udev rules, OR have the zdev initramfs script remove those rules (somewhat of
[Kernel-packages] [Bug 2044104] [NEW] [UBUNTU 20.04] chzdev -e is rebuilding initramfs even with zdev:early=0 set
You have been subscribed to a public bug: Versions: Ubuntu 20.04.5 s390-tools version 2.12.0-0ubuntu3.7.s390x Ubuntu 22.04.2 s390-tools version 2.20.0-0ubuntu3.2.s390x When I configure a zfcp LUN persistently via chzdev, the initrd is being rebuilt even with parameter zdev:early=0 root@a8315003:~# chzdev -e zfcp-lun 0.0.1803:0x500507630910d430:0x40194092 zdev:early=0 zFCP LUN 0.0.1803:0x500507630910d430:0x40194092 configured Note: The initial RAM-disk must be updated for these changes to take effect: - zFCP LUN 0.0.1803:0x500507630910d430:0x40194092 update-initramfs: Generating /boot/initrd.img-5.15.0-60-generic I: The initramfs will attempt to resume from /dev/dasdb1 I: (UUID=e70ecb80-4d1e-4074-9cda-ce231ad6e698) I: Set the RESUME variable to override this. Using config file '/etc/zipl.conf' Building bootmap in '/boot' Adding IPL section 'ubuntu' (default) Preparing boot device: dasda (c00a). Done. root@a8315003:~# == Comment: - Thorsten Diehl - 2023-03-01 06:55:47 == @BOE-dev This behaviour is unexpected. https://www.ibm.com/docs/en/linux-on-systems?topic=commands-chzdev says: Activating a device early during the boot process Use the zdev:early device attribute to activate a device early during the boot process and to override any existing auto-configuration with a persistent device configuration. zdev:early=1 The device is activated during the initial RAM disc phase according to the persistent configuration. zdev:early=0 The device is activated as usual during the boot process. This is the default. If auto-configuration data is present, the device is activated during the initial RAM disc phase according to the auto-configuration. I can't interprete a SCSI LUN as a device with auto configuration data. (At least, if the zfcp device hasn't NPIV enabled) == Comment: #5 - Peter Oberparleiter - 2023-03-01 11:18:28 == (In reply to comment #2) > @BOE-dev > This behaviour is unexpected. > https://www.ibm.com/docs/en/linux-on-systems?topic=commands-chzdev says: > Activating a device early during the boot process > > Use the zdev:early device attribute to activate a device early during the > boot process and to override any existing auto-configuration with a > persistent device configuration. > > zdev:early=1 > The device is activated during the initial RAM disc phase according to > the persistent configuration. > > zdev:early=0 > The device is activated as usual during the boot process. This is the > default. If auto-configuration data is present, the device is activated > during the initial RAM disc phase according to the auto-configuration. The documentation is incorrect for Ubuntu. Canonical specifically builds zdev in a way that every change to persistent device configuration causes an update to the initial RAM-disk. See also: https://bugzilla.linux.ibm.com/show_bug.cgi?id=187578#c35 https://github.com/ibm-s390-linux/s390-tools/commit/7dd03eaeecdd0e2674f145aca34be1275d291bd8 > I can't interprete a SCSI LUN as a device with auto configuration data. (At > least, if the zfcp device hasn't NPIV enabled) This is related to auto-configuration as implemented for DPM. == Comment: #6 - Thorsten Diehl - 2023-03-03 12:41:44 == So, IIUC, chzdev is built for Ubuntu with ZDEV_ALWAYS_UPDATE_INITRD=1, which make the parameter zdev:early=0 ineffective. Correct? If you confirm, you may also close this bug. Not nice - then we have to find an alternate solution. == Comment: #7 - Peter Oberparleiter - 2023-03-07 06:48:07 == (In reply to comment #6) > So, IIUC, chzdev is built for Ubuntu with ZDEV_ALWAYS_UPDATE_INITRD=1, which > make the parameter zdev:early=0 ineffective. Correct? > If you confirm, you may also close this bug. > > Not nice - then we have to find an alternate solution. chzdev -p on Ubuntu will by default rebuild the initrd. This is intended behavior by Canonical and controlled by the ZDEV_ALWAYS_UPDATE_INITRD build-time switch. You can suppress it by adding option --no-root-update to the command line. Specifying zdev:early=0 to chzdev has exactly the effect that it is supposed to have: it tells zdev not to enable that device during initrd processing, resulting in the corresponding udev rule not being copied to the initrd [1]. Unfortunately there is another Ubuntu-initrd script [2] that simply copies ALL udev rules, including those created by zdev, into the initrd. As a result, zdev's early-attribute handling is rendered useless and all devices are enabled, even if a user specified zdev:early=0. Since this bug report indicates that there is a use-case for this function in Ubuntu, it might be worth asking Canonical if current processing could be changed to provide a way for users to specify that a device should specifically NOT be enabled within initrd processing. Technically this could easily be done: 1) Have the generic udev initramfs script not copy zdev-generated Udev rules, OR have the zdev initramfs script remove
