root FS on ZFS, feasible?

[ChrisO]

I hardly dare fo ask: is there anybody out there having root FS on ZFS?
 

[xwiggen]

The root fs is reproducable from external sources and the simpler the faster, why would you need such an advanced fs?

 

[ChrisO]

Fun? :-) Because it is so sophisticated? Built-in RAID/LVM? Snapshots?

On all my Linux computers where there is space for more than one disk I use LVM on top of software RAID. Now I wanted to give ZFS a try as it seams to be really ready.

And also because I spent several years of my life as admin of Solaris systems with zones on ZFS and it was fun.

 

[Igor]

1 hour ago, ChrisO said:

as it seams to be really ready.

For having a rootfs, a bit more work has to be done.

 

1 hour ago, ChrisO said:

Fun? :-)

 

We pushed it very far but here fun stops - its impossible to waste months working only on this and without receiving anything in return. Bills has to be paid ... If you have strength, capacity and will to pick it up and push forward:

https://github.com/armbian/build/pull/2414

https://github.com/armbian/build/pull/2410

This is needed if you want to have zfs rootfs.

[ChrisO]

If after reading conversations you pointed me to, I don’t understand what the problem is, means I don’t have enough expertise in this area to be able to really help.

I don’ t want to waste your precious time, but one thing bugs me:

 

root@odroidhc4:/boot# lsinitramfs initrd.img-5.10.57-meson64|grep -i zfs

conf/conf.d/zfs

etc/default/zfs

etc/zfs

etc/zfs/zfs-functions

etc/zfs/zpool.cache

scripts/local-top/zfs

scripts/zfs

usr/bin/zfsunlock

usr/lib/aarch64-linux-gnu/libzfs.so.4

usr/lib/aarch64-linux-gnu/libzfs.so.4.0.0

usr/lib/aarch64-linux-gnu/libzfs_core.so.3

usr/lib/aarch64-linux-gnu/libzfs_core.so.3.0.0

usr/lib/modules/5.10.57-meson64/updates/dkms/zfs.ko

usr/sbin/mount.zfs

usr/sbin/zfs

 

So it looks like the necessary stuff is there and AFAIK u-boot understand ZFS (will verify it).

What am I missing?

Be gracious with me, just want to understand.

 

[xwiggen]

On 8/16/2021 at 6:31 PM, ChrisO said:

Fun? :-) Because it is so sophisticated? Built-in RAID/LVM? Snapshots?

On all my Linux computers where there is space for more than one disk I use LVM on top of software RAID. Now I wanted to give ZFS a try as it seams to be really ready.

And also because I spent several years of my life as admin of Solaris systems with zones on ZFS and it was fun.

 

AFAIK ZFS for linux will never be ready unless Oracle resolves licensing issues. BTRFS has these features (except some RAID modes perhaps) and is stable.

[TangerineToupée]

I'm working on it, but I make no promises.

 

I've written a script that generates a btrfs-, zfs-, or xfs-based Armbian image from a default (ext4-based) Armbian image. It works on ODroid N2+ and NanoPi Neo3. It probably works on others, but I haven't tried them yet.

 

At present, the generated image uses a boot partition of ext4 and a root partition of ext4/btrfs/xfs/zfs. So, it's not purely ___fs; it does use boot partition of good old ext4.

 

The zfs image doesn't work yet. It will. 

 

Are you looking to run your OS on a 100% zfs filesystem, or are you willing to use an ext4 boot partition and a zfs root partition?

[ChrisO]

Sorry the poor answer time, I am in a quite complicated move process. I haven't had much time to "work" on it.

Boot from any FS would be OK for me, just have ZFS for the OS/user would do it.

Would you mind to share more details on what you achived with us?

[TangerineToupée]

I'm attaching a bash script that generates a ZFS-based Armbian OS image. It works (for me). Try it out and let me know how you get on. I'm in the process of porting it to Python, but the existing bash script is... not terrible. For some reason, I've failed to persuade this website to notify me when someone replies to this thread. 

fructify.20211011.sh.gz