Hello good people,

Hoping this is an appropriate place for troubleshooting questions, I’m learning Linux & OpenZFS in preparation of a server + NAS build, currently working in VMware Workstation. I have successfully setup OpenZFS on Fedora 39 and have configured my zpool using virtual disks.

Now I am looking to replicate the setup on Fedora Silverblue: setup OpenZFS, import the existing disks, then attach the zpool.

1. Import the OpenZFS repository

rpm-ostree install -y https://zfsonlinux.org/fedora/zfs-release-2-4$(rpm --eval "%{dist}").noarch.rpm

2. Confirmed zfs-fuse is not used

rpm-ostree override remove zfs-fuse

error: Package "zfs-fuse" not found
3. Layer the kernel headers

rpm-ostree install kernel-devel

4. Layer OpenZFS

rpm-ostree install zfs

5. Confirmed status

rpm-ostree status

State: idle
Deployments:
● fedora:fedora/39/x86_64/kinoite
                  Version: 39.20240304.0 (2024-03-04T00:39:42Z)
               BaseCommit: b30269aa0e2604e24fd74596a75ee79ef77e6bc2b20f87b49d02f2796ccd3da2
             GPGSignature: Valid signature by E8F23996F23218640CB44CBE75CF5AC418B8E74C
          LayeredPackages: kernel-devel zfs
            LocalPackages: zfs-release-2-4.fc39.noarch
6. I was expecting the next step to fail

modprobe zfs

modprobe: FATAL: Module zfs not found in directory /lib/modules/6.7.7-200.fc39.x86_64

Nevertheless, I went ahead and created the 2 zfs.conf files as described in the OpenZFS documentation.

cat /etc/modules-load.d/zfs.conf
zfs
cat /etc/dnf/protected.d/zfs.conf
zfs

7. This is where I am now stuck

I have tired a number of things such as:

i. Adding modprobe as a kernel argument similar to Silverblue using nVidia drivers

rpm-ostree kargs --append=modprobe=zfs

rpm-ostree kargs
rhgb quiet root=UUID=cbaf12f4-d5b4-4d24-83d6-83ad53730f2a rootflags=subvol=root rw ostree=/ostree/boot.1/fedora/5d2cc07d31373ad2a64ab4ed610ce5a45625bd317c1447d2947a489056a5c077/0 modprobe=zfs

ii. Installed, then disabled, rpm-ostree initramfs, continuing instead with initramfs-etc as described here

rpm-ostree initramfs-etc --track=/etc/modules-load.d/zfs.conf
rpm-ostree initramfs-etc --track=/etc/dnf/protected.d/zfs.conf

rpm-ostree status
State: idle
Deployments:
● fedora:fedora/39/x86_64/kinoite
                  Version: 39.20240304.0 (2024-03-04T00:39:42Z)
               BaseCommit: b30269aa0e2604e24fd74596a75ee79ef77e6bc2b20f87b49d02f2796ccd3da2
             GPGSignature: Valid signature by E8F23996F23218640CB44CBE75CF5AC418B8E74C
          LayeredPackages: kernel-devel zfs
            LocalPackages: zfs-release-2-4.fc39.noarch
             InitramfsEtc: /etc/dnf/protected.d/zfs.conf /etc/modules-load.d/zfs.conf
8. zfs, zpool seem ok as I can get the help output or read the man pages, however:

zpool status
The ZFS modules cannot be auto-loaded.
Try running 'modprobe zfs' as root to manually load them.

zfs get all
The ZFS modules cannot be auto-loaded.
Try running 'modprobe zfs' as root to manually load them.

Obviously, I’m missing something due to my gaps in experience with Linux. I see that Universal Blue has incorporated OpenZFS as described on the GitHub page, so it should be possible for me to achieve this as well, I suppose.

Any pointers, documentation or advice is appreciated!

    • @iotzanOP
      link
      210 months ago

      Thank you! This is the page where I discovered that I can try rpm-ostree kargs --append=modprobe=zfs, which didn’t work.
      Still, as far as I understand it, ublue managed to overcome this, as they do offer a Fedora version with zfs included.
      What am I missing?

  • @[email protected]
    link
    fedilink
    3
    edit-2
    10 months ago

    I don’t use Fedora, but I have ZFS on all my Arch systems for everything (including root fs). So, I’ll make a guess - is the package you installed for ZFS a DKMS kernel module, or a binary one? That’s the first thing. If it’s a DKMS module, I don’t see anything on your output showing it was compiled, which would explain the module not loading. If it’s a binary module in that package, it must be for the exact same version of the kernel that is installed - exact same. If it mismatches then you need either a different kennel or different ZFS package. In either case, you’ll probably need to wire in a hook for your initramfs, but it looks that part might be ok from your output. Hope that helps, good luck. ZFS is incredibly good.

    • @iotzanOP
      link
      110 months ago

      This is where my knowledge of Linux falls short.

      is the package you installed for ZFS a DKMS kernel module, or a binary one?

      In both Fedora and Silverblue I find the same, ZFS-related files, under /usr/sbin/

       Jan  1  1970 blkzone
      lrwxrwxrwx. 43 root root      11 Feb 28 13:59 cache_metadata_size -> pdata_tools
      -rwxr-xr-x.  3 root root   24176 Jan  1  1970 fatresize
      -rwxr-xr-x.  3 root root     756 Jan  1  1970 fsck.zfs
      -rwxr-xr-x.  3 root root   15960 Jan  1  1970 fsfreeze
      lrwxrwxrwx. 91 root root       3 Feb 28 13:59 lvresize -> lvm
      -rwxr-xr-x.  3 root root   24104 Jan  1  1970 mount.zfs
      lrwxrwxrwx.  3 root root      22 Feb 28 13:59 named-checkzone -> ../bin/named-checkzone
      lrwxrwxrwx.  3 root root      24 Feb 28 13:59 named-compilezone -> ../bin/named-compilezone
      -rwxr-xr-x.  3 root root   32568 Jan  1  1970 nilfs-resize
      -rwxr-xr-x.  3 root root   69672 Jan  1  1970 ntfsresize
      lrwxrwxrwx. 91 root root       3 Feb 28 13:59 pvresize -> lvm
      -rwxr-xr-x.  3 root root   73784 Jan  1  1970 resize2fs
      lrwxrwxrwx. 11 root root       9 Feb 28 13:59 resize.f2fs -> fsck.f2fs
      -rwxr-xr-x.  3 root root   24408 Jan  1  1970 resizepart
      lrwxrwxrwx. 43 root root      11 Feb 28 13:59 thin_metadata_size -> pdata_tools
      -rwxr-xr-x.  3 root root     804 Jan  1  1970 xfs_freeze
      -rwxr-xr-x.  3 root root  212440 Jan  1  1970 zdb
      -rwxr-xr-x.  3 root root  107736 Jan  1  1970 zed
      -rwxr-xr-x.  3 root root  149984 Jan  1  1970 zfs
      -rwxr-xr-x.  3 root root   15920 Jan  1  1970 zfs_ids_to_path
      -rwxr-xr-x.  3 root root   15920 Jan  1  1970 zgenhostid
      -rwxr-xr-x.  3 root root   32472 Jan  1  1970 zhack
      -rwxr-xr-x.  3 root root   65400 Jan  1  1970 zic
      -rwxr-xr-x.  3 root root   36536 Jan  1  1970 zinject
      -rwxr-xr-x.  3 root root  264288 Jan  1  1970 zpool
      -rwxr-xr-x.  3 root root   57688 Jan  1  1970 zramctl
      -rwxr-xr-x.  3 root root   40720 Jan  1  1970 zstream
      lrwxrwxrwx.  3 root root       7 Mar  4 10:20 zstreamdump -> zstream
      -rwxr-xr-x.  3 root root  162208 Jan  1  1970 ztest
      -rwxr-xr-x.  3 root root   53384 Jan  1  1970 zvbid
      

      Also, ztest does something

      verifying concrete vdev 0, metaslab 11 of 12 ...
      loading concrete vdev 0, metaslab 11 of 12 ...
      verifying concrete vdev 0, metaslab 11 of 12 ...
      

      I assume, therefor, that OpenZFS exists, however the kernel is not loading the related module.
      Binary, library or something else - how can I tell?

    • @[email protected]
      link
      fedilink
      110 months ago

      It’s worth noting OP is on Fedora Silverblue - an “immutable” distro in which the system files are typically not editable.

  • @[email protected]
    link
    fedilink
    210 months ago

    Unfortunately this is why I chose to run Ubuntu server. As far as I know, it’s the only distro with ZFS set up by default. I wish you luck, as I run Silverblue as my desktop and would love to run it for my server too!

    • @iotzanOP
      link
      210 months ago

      I chose Fedora since I’m most familiar with RedHat from my professional activities.

      • @[email protected]
        link
        fedilink
        English
        110 months ago

        I would recommend AlmaLinux in that case. It takes the place of CentOS, which was the free edition of Red Hat. Fedora is targeted at the desktop, not servers.

        You could do it, but I haven’t heard about people using Silverblue as a server yet.

        • @[email protected]
          link
          fedilink
          110 months ago

          Fedora has another immutable variant for servers called CoreOS. It’s the default distro on any OKD cluster, though I run a derivative of it from ublue called ucore, which has a variant for zfs.

  • @[email protected]
    link
    fedilink
    210 months ago

    You wouldn’t use Silverblue on a server, you’d use Fedora CoreOS (FCOS) or CentOS Stream CoreOS (COSS). The ublue project has a FCOS derivative called ucore with options for ZFS OOTB. I use it on my server.

    There’s some examples on how you’d use dockerfiles to build a ZFS module (as well as other things) from Fedora as well.

    In any case, building bootable container images containing stuff like kernel modules is currently how this type of thing is done on atomic Fedora variants.