ZFS module is installed for wrong kernel on arm64-raspi3 systems (19.04 beta)

[Lasse]

Platform: Raspberry Pi 3 running ubuntu-19.04-beta-preinstalled-server-arm64+raspi3.img

Kernel: Default (Linux ubuntu 4.18.0-1010-raspi2 #12-Ubuntu SMP PREEMPT Tue Feb 12 12:17:11 UTC 2019 aarch64 aarch64 aarch64 GNU/Linux)

Problem: The ZFS module is installed for a kernel that can not be used.

apt-get install zfs-initramfs
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
  libnvpair1linux libuutil1linux libzfs2linux libzpool2linux
  linux-image-unsigned-5.0.0-8-snapdragon
  linux-modules-5.0.0-8-snapdragon zfs-zed zfsutils-linux
Suggested packages:
  fdutils linux-doc-5.0.0 | linux-source-5.0.0 linux-tools
  linux-headers-5.0.0-8-snapdragon nfs-kernel-server
  samba-common-bin
The following NEW packages will be installed:
  libnvpair1linux libuutil1linux libzfs2linux libzpool2linux
  linux-image-unsigned-5.0.0-8-snapdragon
  linux-modules-5.0.0-8-snapdragon zfs-initramfs zfs-zed
  zfsutils-linux
0 upgraded, 9 newly installed, 0 to remove and 0 not upgraded.
Need to get 55.7 MB of archives.
After this operation, 305 MB of additional disk space will be used.
Do you want to continue? [Y/n] Y
Get:1 http://ports.ubuntu.com/ubuntu-ports disco/main arm64 linux-modules-5.0.0-8-snapdragon arm64 5.0.0-8.9 [47.5 MB]
Get:2 http://ports.ubuntu.com/ubuntu-ports disco/main arm64 linux-image-unsigned-5.0.0-8-snapdragon arm64 5.0.0-8.9 [7169 kB]
Get:3 http://ports.ubuntu.com/ubuntu-ports disco/main arm64 libnvpair1linux arm64 0.7.12-1ubuntu5 [42.8 kB]
Get:4 http://ports.ubuntu.com/ubuntu-ports disco/main arm64 libuutil1linux arm64 0.7.12-1ubuntu5 [50.7 kB]
Get:5 http://ports.ubuntu.com/ubuntu-ports disco/main arm64 libzpool2linux arm64 0.7.12-1ubuntu5 [498 kB]
Get:6 http://ports.ubuntu.com/ubuntu-ports disco/main arm64 libzfs2linux arm64 0.7.12-1ubuntu5 [121 kB]
Get:7 http://ports.ubuntu.com/ubuntu-ports disco/main arm64 zfsutils-linux arm64 0.7.12-1ubuntu5 [267 kB]
Get:8 http://ports.ubuntu.com/ubuntu-ports disco/main arm64 zfs-initramfs arm64 0.7.12-1ubuntu5 [22.2 kB]
Get:9 http://ports.ubuntu.com/ubuntu-ports disco/main arm64 zfs-zed arm64 0.7.12-1ubuntu5 [57.5 kB]
Fetched 55.7 MB in 37s (1486 kB/s)
Selecting previously unselected package linux-modules-5.0.0-8-snapdragon.
(Reading database ... 61671 files and directories currently installed.)
Preparing to unpack .../0-linux-modules-5.0.0-8-snapdragon_5.0.0-8.9_arm64.deb ...
Unpacking linux-modules-5.0.0-8-snapdragon (5.0.0-8.9) ...
Selecting previously unselected package linux-image-unsigned-5.0.0-8-snapdragon.
Preparing to unpack .../1-linux-image-unsigned-5.0.0-8-snapdragon_5.0.0-8.9_arm64.deb ...
Unpacking linux-image-unsigned-5.0.0-8-snapdragon (5.0.0-8.9) ...
Selecting previously unselected package libnvpair1linux.
Preparing to unpack .../2-libnvpair1linux_0.7.12-1ubuntu5_arm64.deb ...
Unpacking libnvpair1linux (0.7.12-1ubuntu5) ...
Selecting previously unselected package libuutil1linux.
Preparing to unpack .../3-libuutil1linux_0.7.12-1ubuntu5_arm64.deb ...
Unpacking libuutil1linux (0.7.12-1ubuntu5) ...
Selecting previously unselected package libzpool2linux.
Preparing to unpack .../4-libzpool2linux_0.7.12-1ubuntu5_arm64.deb ...
Unpacking libzpool2linux (0.7.12-1ubuntu5) ...
Selecting previously unselected package libzfs2linux.
Preparing to unpack .../5-libzfs2linux_0.7.12-1ubuntu5_arm64.deb ...
Unpacking libzfs2linux (0.7.12-1ubuntu5) ...
Selecting previously unselected package zfsutils-linux.
Preparing to unpack .../6-zfsutils-linux_0.7.12-1ubuntu5_arm64.deb ...
Unpacking zfsutils-linux (0.7.12-1ubuntu5) ...
Selecting previously unselected package zfs-initramfs.
Preparing to unpack .../7-zfs-initramfs_0.7.12-1ubuntu5_arm64.deb ...
Unpacking zfs-initramfs (0.7.12-1ubuntu5) ...
Selecting previously unselected package zfs-zed.
Preparing to unpack .../8-zfs-zed_0.7.12-1ubuntu5_arm64.deb ...
Unpacking zfs-zed (0.7.12-1ubuntu5) ...
Setting up libuutil1linux (0.7.12-1ubuntu5) ...
Setting up linux-modules-5.0.0-8-snapdragon (5.0.0-8.9) ...
Setting up linux-image-unsigned-5.0.0-8-snapdragon (5.0.0-8.9) ...
I: /boot/vmlinuz is now a symlink to vmlinuz-5.0.0-8-snapdragon
I: /boot/initrd.img is now a symlink to initrd.img-5.0.0-8-snapdragon
Setting up libnvpair1linux (0.7.12-1ubuntu5) ...
Setting up libzpool2linux (0.7.12-1ubuntu5) ...
Setting up libzfs2linux (0.7.12-1ubuntu5) ...
Setting up zfsutils-linux (0.7.12-1ubuntu5) ...
Created symlink /etc/systemd/system/zfs-import.target.wants/zfs-import-cache.service → /lib/systemd/system/zfs-import-cache.service.
Created symlink /etc/systemd/system/zfs-mount.service.wants/zfs-import.target → /lib/systemd/system/zfs-import.target.
Created symlink /etc/systemd/system/zfs.target.wants/zfs-import.target → /lib/systemd/system/zfs-import.target.
Created symlink /etc/systemd/system/zfs-mount.service.wants/zfs-load-module.service → /lib/systemd/system/zfs-load-module.service.
Created symlink /etc/systemd/system/zfs.target.wants/zfs-load-module.service → /lib/systemd/system/zfs-load-module.service.
Created symlink /etc/systemd/system/zfs-share.service.wants/zfs-mount.service → /lib/systemd/system/zfs-mount.service.
Created symlink /etc/systemd/system/zfs.target.wants/zfs-mount.service → /lib/systemd/system/zfs-mount.service.
Created symlink /etc/systemd/system/zfs.target.wants/zfs-share.service → /lib/systemd/system/zfs-share.service.
Created symlink /etc/systemd/system/multi-user.target.wants/zfs.target → /lib/systemd/system/zfs.target.
zfs-import-scan.service is a disabled or a static unit, not starting it.
Job for zfs-load-module.service failed because the control process exited with error code.
See "systemctl status zfs-load-module.service" and "journalctl -xe" for details.
A dependency job for zfs-import-cache.service failed. See 'journalctl -xe' for details.
Job for zfs-mount.service failed because the control process exited with error code.
See "systemctl status zfs-mount.service" and "journalctl -xe" for details.
Job for zfs-share.service failed because the control process exited with error code.
See "systemctl status zfs-share.service" and "journalctl -xe" for details.
Setting up zfs-initramfs (0.7.12-1ubuntu5) ...
Setting up zfs-zed (0.7.12-1ubuntu5) ...
Created symlink /etc/systemd/system/zed.service → /lib/systemd/system/zfs-zed.service.
Created symlink /etc/systemd/system/zfs.target.wants/zfs-zed.service → /lib/systemd/system/zfs-zed.service.
Processing triggers for libc-bin (2.29-0ubuntu1) ...
Processing triggers for man-db (2.8.5-2) ...
Processing triggers for initramfs-tools (0.131ubuntu18) ...
update-initramfs: Generating /boot/initrd.img-4.18.0-1010-raspi2
Using DTB: bcm2710-rpi-3-b.dtb
Installing /lib/firmware/4.18.0-1010-raspi2/device-tree/broadcom/bcm2710-rpi-3-b.dtb into /boot/dtbs/4.18.0-1010-raspi2/bcm2710-rpi-3-b.dtb
Taking backup of bcm2710-rpi-3-b.dtb.
Installing new bcm2710-rpi-3-b.dtb.
Ignoring old or unknown version 4.18.0-1010-raspi2 (latest is 5.0.0-8-snapdragon)
Processing triggers for linux-image-unsigned-5.0.0-8-snapdragon (5.0.0-8.9) ...
/etc/kernel/postinst.d/initramfs-tools:
update-initramfs: Generating /boot/initrd.img-5.0.0-8-snapdragon
Using DTB: bcm2710-rpi-3-b.dtb
Couldn't find DTB bcm2710-rpi-3-b.dtb on the following paths: /etc/flash-kernel/dtbs /usr/lib/linux-image-5.0.0-8-snapdragon /lib/firmware/5.0.0-8-snapdragon/device-tree/
Installing into /boot/dtbs/5.0.0-8-snapdragon/bcm2710-rpi-3-b.dtb
cp: cannot stat '': No such file or directory
run-parts: /etc/initramfs/post-update.d//flash-kernel exited with return code 1
run-parts: /etc/kernel/postinst.d/initramfs-tools exited with return code 1
dpkg: error processing package linux-image-unsigned-5.0.0-8-snapdragon (--configure):
 installed linux-image-unsigned-5.0.0-8-snapdragon package post-installation script subprocess returned error exit status 1
Errors were encountered while processing:
 linux-image-unsigned-5.0.0-8-snapdragon
E: Sub-process /usr/bin/dpkg returned an error code (1)

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1822797/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Steve Langasek (vorlon)]

This is because the raspi2 kernel package does not Provides: zfs-dkms, zfs-modules, as expected for Ubuntu kernel packages which include ZFS support. So if you try to install the zfs-initramfs package, apt will try to pull in something which satisfies the dependencies if nothing else is already installed which does, and it doesn't know that the kernel image it's pulling is not an appropriate provider of zfs for the running system.

If there is a bug here, it's that the Ubuntu zfs sauce patches are not enabled on the raspi2 arm64 kernel build.

However, given the memory limitations of the raspi3 family of devices, I'm not sure it's at all advisable to try to run zfs on such a system.

[Lasse (lars-engblom)]

I have had good experience with running ZFS on rpi3 using other distros. Of course it would be a complete craziness to use zfs in a desktop setup with just 1Gb of RAM. For what rpi is actually meant, 1Gb is plenty enough to run ZFS especially if the ARC size is set to a smaller value.

This is why I hope this problem would get fixed, so I am able to use Ubuntu on all platforms.

[satmandu (satadru-umich)]

For what it is worth, zfs works quite well for a root fs rpool on a 4Gb RPI4b.