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OpenZFS Documentation
https://openzfs.github.io/openzfs-docs/
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NixOS, Alpine Linux: mount datasets in Root on ZFS guide; immutable root; GRUB update #410

Closed ghost closed 1 year ago

ghost commented 1 year ago

Acknowledgement: @bjornstromberg Closes #398

ghost commented 1 year ago

Upstream also does not support Root on ZFS at all. At least I was unable to find any such option in the installer shipped in the live media. Does this fact render the whole guide obsolete? It does not, of course.

In the case of other distros, Debian, Ubuntu, Fedora, RHEL, Alpine, it is precisely because the lack of upstream support that the guides here were written.

For your information, if you look inside the repo to see what that my.boot.immutable option does, it only changes how the datasets are mounted, nothing fancy:

https://github.com/ne9z/dotfiles-flake/blob/058bef759b26c1d37bfb4998f532db8358e71da7/modules/boot/default.nix#L88

I do not think dropping this feature, which is very popular among root on ZFS users, is a good idea.

Sandro @.***> writes:

@SuperSandro2000 commented on this pull request.

+You can enable immutable root by setting my.boot.immutable option +inside the flake to true. Set to false reverts to +non-immutable root file system. Defaults to false.

This is not something that upstream NixOS supports.

-- Reply to this email directly or view it on GitHub: https://github.com/openzfs/openzfs-docs/pull/410#pullrequestreview-1367873889 You are receiving this because you authored the thread.

Message ID: @.***>

SuperSandro2000 commented 1 year ago

Upstream also does not support Root on ZFS at all.

It does, I am running it on multiple machines and I am writting this comment from a ZFS on root machine.

At least I was unable to find any such option in the installer shipped in the live media.

The installer does not have ZFS support but you can manually format and configure like before.

For your information, if you look inside the repo to see what that my.boot.immutable option does, it only changes how the datasets are mounted, nothing fancy:

This is not something upstream NixOS supports or tests for. This could just fall apart in the future because it is not accounted for when tests are run.

ghost commented 1 year ago

Sandro @.***> writes:

Upstream also does not support Root on ZFS at all.

It does, I am running it on multiple machines and I am writting this comment from a ZFS on root machine.

Immutable root is supported by upstream because I am running it on my three laptops and home server and I am writting this comment from a immutable ZFS on root machine for over two years and four releases.

No less valid than your logic.

At least I was unable to find any such option in the installer shipped in the live media.

The installer does not have ZFS support but you can manually configure the disk like before.

So what is your definition of upstream Root on ZFS support? I see that, the guide as it is now, runs on my machine, so it is supported.

For your information, if you look inside the repo to see what that my.boot.immutable option does, it only changes how the datasets are mounted, nothing fancy:

This is not something upstream NixOS supports or tests for. This could just fall apart in the future because it is not accounted for when tests are run.

This option, my.boot.immutable, directly, exclusively and only uses config.fileSystems. options. Does NixOS run tests for config.fileSystems. options?

I guess it does, because fileSystems.* options are absolutely critical.

Now, I think we should keep the flake-based approach. You want something clean like:

my.boot.devices = [ "disk1" "disk2" ]

or do you like

fileSystems = { /boot/efis/disk1 = { device = /dev/disk/by-id/disk1; }; /boot/efis/disk2 = { device = /dev/disk/by-id/disk2; }; }

grub.mirroredBoots = { [ "disk1" "disk2" ] }

Because we must support and correctly handle multi-disk installations. This is what ZFS is all about.

ghost commented 1 year ago

If you agree that we should keep the modules and flake, then we can discuss the other issues you mentioned in the other PR.

NixOS allows using multiple programs to manage your network settings, so not everyone necessarily has network manager installed.

Please read what is inside the cloned repo before commenting.

NetworkManager is enabled by default for all users who has cloned the repo. This is done out of consideration of wireless network users. If not enabled, wireless network is not possible with minimal NixOS installation profile.

If you just go ahead and making comments without even looking at what you are talking about, it would be a waste of time for both of us.

Immutable root is not an upstream setting and it shouldn't be recommended in the basic ZFS install guide.

Discussed earlier.

ghost commented 1 year ago

To keep discussion in one place, let's address your other concerns from issue #411:

The NixOS guide right now guides people to clone a dotfiles repo and change some settings in there, instead of explaining what are the relevant settings people should set in their NixOS configuration.

I have replied there that the main draw backs are the following:

Setting up ZFS on NixOS is pretty easy.

Just because you got Root on ZFS installed on your laptop does not mean your approach meets all the requirements of a Root on ZFS documentation. For example, do you have multi-disk and encrypted swap configured? With mirrored bootloader?

Mind you, without utilizing disk arrays, ZFS does not provide any redundancy.

Once the single disk in your pool fails, your data is gone for good.

and IMO cloning some extra config should not be required, as I believe that the guide could fit on one screen in standard text size when leaving out the explanations.

It would not fit in one screen, given all the goals we have set out to accomplish.

There are a handful of module options be taught about and recommended to enable (autoScrub, autoTrim, etc)

This part should be delegated to NixOS wiki. All configuration steps which do not involve repartitioning the disks, changing the pool properties or changing the dataset layout is out-of-scope for this guide.

ghost commented 1 year ago

instead of explaining what are the relevant settings people should set in their NixOS configuration.

We will provide detailed and extensive comments in the flake repo of each custom module and option enabled to provide a guide for users configuring their own system.

The comments are currently missing, because I do not have the time at the moment. Contributions from the community is much appreciated.

ghost commented 1 year ago

@gmelikov It's now ready for merging. PR #412 and #262 can also be closed. The latter is no longer relevant to the current RHEL and Fedora guide.

To @SuperSandro2000: I have removed NetworkManager on your suggestion.

ghost commented 1 year ago

I just received a feedback (#413) about Arch Linux, where the initrd defaults was changed upstream such that the guide no longer boots. Fix added to this PR.