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Comment by kawsper | Hacker News Reader

The problem is the license, which ZFS on Linux covers a bit here: https://github.com/zfsonlinux/zfs/wiki/FAQ#licensing

You can see some of the fun hoops you have to go through to get ZFS as your root filesystem here: https://github.com/zfsonlinux/zfs/wiki/Ubuntu-16.04-Root-on-...

For now I just have 4 disks in a ZFS-raid for storage, and then I have installed my OS on a separate SSD.

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The license is only a problem for gpl. Note that FreeBSD uses zfs and has for quite some time.

Yes - that is true, and it seems like ZFS usage is much higher there because of that.

The problem back when was that Sun wouldn't indemnify Apple against third party patent claims. Now that Solaris is dead it is unclear what Oracle's intentions are, but in any case, surely Apple would have similar desires.

Ubuntu has it built in and ready to go. But not for the root drive (that way lies madness).

It's quite excellent for the root drive, you just have to install via debootstrap. I personally do this on all my 1/2 dozen boxes (Straight Debian usually, but some Ubuntu). I've also written up how to build an AWS AMI this way. Good stuff, It's only going to get easier.

> I've also written up how to build an AWS AMI this way

If you've written it up in public, any chance of a link?

from their submission history: https://scotte.org/2016/12/ZFS-root-filesystem-on-AWS

It's not difficult really (assuming one can/is willing to RTFM), just a little more involved and time-consuming to get set up. I've used ZFS on / on Ubuntu a handful of times and all of the machines I use on a daily basis (a high-end workstation and a pair of laptops, all running Arch Linux) all use ZFS exclusively.

I have one (centos) machine with zfs on /. Looking back, it was a mistake - I always dread, when I see grub update in the yum update list, what will break this time.

And of course, after each kernel update, link your /dev/by-id/... devices into /dev and rerun grub2-mkconfig by hand. Otherwise, you won't boot the new kernel you just updated.

If this machine weren't a pet, it would be wiped clean and reinstalled with xfs /.

Wow. That sounds like something isn't configured quite right. Or perhaps ZFS just isn't as well "integrated" on CentOS.

All of my Linux machines with ZFS are running Arch Linux (as well as a few servers running FreeBSD) and I don't have to do anything special.

For example, I'll update them every few days (or whenever I don't mind having to "re-open" all my applications, tabs, etc.) and I just run "pacaur -Syyu", have it update everything, and reboot when it's done. It starts back up, I enter in my FDE passphrase, and it boots right up.

It is actually a known issue between ZoL and GRUB:

https://github.com/zfsonlinux/grub/issues/5

zpool status will show only basename component of the device name and grub will look for it in /dev only. As I created the pool with ata-* device names, which are constant per device, it will of course fail, because they are in the /dev/by-id/ and grub is not looking for them there.

Next time there is a kernel update, I' going to try the env variable mentioned in the august 2017 comment. Hopefully it will work right.

ZFS and CentOS are not a good combination, in my experience. The Red Hat/Oracle feud doesn't give RH much incentive to be ZFS-friendly, and the interaction between DKMS and weak-modules is a fiasco.

ZFS woes, and Red Hat's penchant for yanking hardware support (like a PERC/4e RAID controller I encountered this spring), have brought me to the point that the only new CentOS installations I'll make will be KVM guests.

The last straw for me was the 1708 release, when the ZFS modules failed to build, leaving my home NAS stuck on the old kernel. Out went CentOS, in went Ubuntu Server. No regrets.

In my case, Ubuntu makes PITA running stuff I want to run (especially FreeIPA/sssd/gssapi integration). On the other hand, I'm using kmod repo for ZoL, not DKMS, because I wanted to avoid having a compiler and dev packages on the server in the first place. CentOS/RHEL have kernel ABIs, why not use them.

That's odd. I've been using it on Ubuntu as the rootfs for over 18 months now and have been through 16.04/16.10/17.04/17.10 upgrades and numerous kernel upgrades and it's worked flawlessly every time.

And that's the thing. I used SmartOS for a while and while there's nothing wrong with a ZFS root, per se, you're still at the mercy of boot loaders and whatever Amazon will or will not let you do.

So I've taken to having ext4 or whatever as the boot drive and a zpool for anything I care about :)

Not really, I use it on Arch as my root drive https://ramsdenj.com/2016/06/23/arch-linux-on-zfs-part-2-ins... and never have a problem. It's been useful multiple times for informing me that I have a problem disc, and being able to go back in time and look at how things have changed on my system with snapshots is of great benefit. Being able to rollback, clone filesystems and send them around is great too.

With archzfs I get binary upgrades with every kernel, and I've never had a problem at boot after a kernel update.

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