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ZFSBootMenu – A boot loader to manage ZFS boot environments for Linux

zfsbootmenu.org

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Re: ZFSBootMenu – A boot loader to manage ZFS boot environments for Linux

#4

Post by hnlmorg »

1letterunixname wrote: post #3

Quoted post unavailable.

Choice is good if it offers something different, which this does because it is more than just a boot menu with ZFS support.

Anyway, since when has Linux been adverse to choice? Multiple different init daemons, window managers, desktop environments, cron daemons, MTAs, scripting languages, shells, etc. even the way you set up a networking interface can differ wildly.

Re: ZFSBootMenu – A boot loader to manage ZFS boot environments for Linux

#5

Post by sirn »

1letterunixname wrote: post #3

Quoted post unavailable.

The problem is, ZFS support on GRUB2 hasn't been great, partly due to CDDL/GPL licensing incompatibility requiring lots of ZFS internals to be re-implemented in GRUB. This resulted in issues such as grub-probe unable to detect ZFS pools due to unsupported ZFS features[1] (including native ZFS encryption, which is a deal-breaker for many)

ZBM took another approach. It provides a small initramfs image that are built on the host machine via standard method such as dracut or mkinitcpio. This image provides an interface for decrypting/mounting ZFS filesystems using the very same ZFS kernel module and tools installed on the host. After the filesystem is mounted, it then kexec'd into the host kernel.

This also means ZBM doesn't completely replaced GRUB2 or syslinux. Instead, it rely on those intermediate bootloader (including EFI bootloader such as rEFId/gummiboot) to load ZBM itself. (Though ZBM itself only has built-in hooks for syslinux and gummiboot).

Being an initramfs give an extra benefit of providing interesting mechanism during boot e.g. providing a SSH server for entering an encryption key on a headless server[2], ability to discover, managing/booting from ZFS snapshots, etc.

(No affiliate; just a very happy user.)

[1]: https://savannah.gnu.org/bugs/?58555

[2]: https://github.com/zbm-dev/zfsbootmenu/wiki/Remote-Access-to...

Re: ZFSBootMenu – A boot loader to manage ZFS boot environments for Linux

#7

Post by hnlmorg »

nailer wrote: post #6

I mean you can’t maintain ZFS normally, and people have been trying to make zfs happen for what… two decades now?

I don’t understand why you’re being snarky. ZFS has been hugely successful since it’s release, and continues to be successful even now. The reason why it’s popular is precisely because it’s easy to maintain.

Re: ZFSBootMenu – A boot loader to manage ZFS boot environments for Linux

#8

Post by fjdiccf »

1letterunixname wrote: post #3

Quoted post unavailable.

Pretty much every single person using Linux or writing open source is doing it specifically because the choices they had were not adequate.

Don't like choice? Go back to Mac, spare us your hot takes.

Re: ZFSBootMenu – A boot loader to manage ZFS boot environments for Linux

#9

Post by matja »

sirn wrote: post #5
1letterunixname wrote: post #3

Quoted post unavailable.

The problem is, ZFS support on GRUB2 hasn't been great, partly due to CDDL/GPL licensing incompatibility requiring lots of ZFS internals to be re-implemented in GRUB. This resulted in issues such as grub-probe unable to detect ZFS pools due to unsupported ZFS features[1] (including native ZFS encryption, which is a deal-breaker for many) ZBM took another approach. It provides a small initramfs image that are built on…

Wouldn't kexec with a mounted filesystem lose the filesystem state because the kernel heap+stack is overwritten? I think ZBM copies the kernel/initramfs from the ZFS dataset (presumably to tmpfs), unmounts/exports, then kexec's, and the new initramfs imports/mounts the pool/dataset as usual?
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