Documentation with guidance on how often to upgrade ZBM and how

[timkgh]

Any guidance on how often to update ZBM and how to do it, e.g. running on Ubuntu 22.04?
Any consideration for a PPA that would make this management easier?

[zdykstra]

Upgrading ZFSBootMenu depends on the method of installation. When you do it largely depends on two factors:

1. Are there new features or bug fixes that I need?
2. Is the version of ZFS in ZFSBootMenu now too old for my system?

You're likely fine for some time - Ubuntu 22.04 doesn't ship a very recent version of ZFS, so there shouldn't be any pool compatibility issues.

We won't be providing a PPA or any other distro-specific packaging infrastructure.

[timkgh]

FWIW I want to thank you for writing the portable ZBM instructions! ❤️
It helped me boot from ZFS again, I just ran into this grub issue:
openzfs/zfs#13873 (comment)

Now I'm trying to figure out what to do with /boot. Move it to its own bpool (which IIUC would prevent me from using ZBM), switch to ZBM, move /boot to ext4 and avoid future grub issues.

[zdykstra]

Using a dedicated /boot dataset (either on the same pool, or a different one) would prevent ZFSBootMenu from booting your system; it needs /boot to be a sub-directory of a dataset that mounts to /.

We're obviously biased, but you'd be fine running ZFSBootMenu with Ubuntu. It needs fairly infrequent updates and worst case, as you've noted, you can just throw a copy on to a USB drive and boot your system.

[timkgh]

Ubuntu 22.04 doesn't ship a very recent version of ZFS, so there shouldn't be any pool compatibility issues

Any guidance for the upcoming 24.04 which I'll probably move to later this year?

[classabbyamp]

appears to be 2.2.2, which would work with the current prebuilt images.

[Piotr2009]

hello) thanks for a great work ! installed on debian 12.2 bookworm . lost some time and efforts when following from the start the tutorial of openzfs for debian , dual pools bootfs/rootfs is not the case here. Question - should i expect problems when upgrading debian to trixie , thats version 13 . I have compiled from source zfsbootmenu . Is it supported or better not-go ? . thanks

[zdykstra]

I haven't tried building ZFSBootMenu from source on Debian 13, so I can't explicitly say that it will work. However, I would expect that it'll continue to work with out any real issues. If you do run into problems with it, feel free to create a new discussion and we can possibly help you work through the problem.

[Piotr2009]

Super ! the upgrade went flawlessly . i'm very happy. debian bookworm -> trixie Update , upgrade, plus zbm-generate and viola . чудово)

[timkgh]

Any tutorial with clear steps on how to replace GRUB with ZBM on Ubuntu? Or maybe not replace but rather have the option to boot from either, if one is broken, there's the other one as a backup.
I have a high level idea on how things work, but I'm interested in the details, how to properly configure it, auto boot an entry (after some timeout that lets me select a different kernel), what happens when Ubuntu updates the kernel, do I need to manually do something with ZBM to be able to boot the previous kernel version if the new one has issues, etc.

[timkgh]

I need to figure out what kernel params I may need to pass, whatever grub used to pass, if anything, though just booting from the portable ZBM seems to work just fine, so perhaps just stay with the simplest defaults, nothing to configure.

[timkgh]

Posting here, hopefully others discover it too and also to check my work ...

It appears grub passes the following kernel params (from /boot/grub/grub.cfg menu entries because I cannot boot it):
linux "/ROOT/ubuntu@/boot/vmlinuz-6.5.0-14-generic" root=ZFS="rpool/ROOT/ubuntu" ro fbcon=font:TER16x32 crashkernel=512M-:192M

ZBM passed these params (from cat /proc/cmdline of a live system booted with ZBM defaults):
root=zfs:rpool/ROOT/ubuntu quiet loglevel=4 spl.spl_hostid=0x...

The format of root= is different but looks reasonable and perhaps alternate syntax, ro is the default anyway IIUC and the rest not sure they really matter in practice.

I'll remove quiet loglevel=4 from ZBM because I like a verbose boot to notice errors.

Not sure what value the bootfs property should have. My rpool doesn't have it set at all. Does it matter to set it? I have another zpool on the system, but it's just storage it doesn't have any kernels, etc.
Edit: found it here:

bootfs=(unset)|pool[/dataset]
Identifies the default bootable dataset for the root pool. This property is expected to be set mainly by the installation and upgrade programs. Not all Linux distribution boot processes use the bootfs property.

Looks like I need to set bootfs=rpool/ROOT/ubuntu

[classabbyamp]

root and spl.spl_hostid are added by zbm when booting so they should not be included when setting the dataset property

[zdykstra]

You can set bootfs in the ZBM interface via MOD+D, otherwise you can do it via zpool set .... Once that's set, that dataset will automatically boot with out any required user interaction.

[timkgh]

I got it all working to my liking. Amazing piece of software! Thank you so much for all your work. ❤️