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Comment by stiray | Hacker News Reader

I have submitted multiple bugs for ZoL, from prohibiting boot of zfs as root (for the sake of boot beeing faster (?) they are not doing zpool import -a(f) but rather rely on cache file which is... crazy). Also the .zfs/snapshot still doesnt work. Both are vital issues and still not beeing fixed.

Boot on Linux laptop now looks like:

- power on

- wait for recovery shell

- `zpool import -a`

- `exit`

In all my years I have never observed this on FreeBSD and... as I have said, I expect from FreeBSD to be rock solid and it never dissapointed.

ZoL? I wouldn't be running it on my linux servers for a while. The basic mistakes that they are doing are not something that apriciate from file system that is meant to be as reliable as possible.

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The actual problem you are having is that there isn't a setup option on virtually any distro that will set this up for you but you are clearly setup incorrectly. I was using Funtoo with a zfs root for years until the machines CPU died.

The process of booting up looked like hit power button wait for desktop to show up. The "basic mistakes they are doing" are completely a function of your distro not having a way to easily set this up and you not knowing how to use it correctly. As far as I know the only distro that supports zfs on root via its installer is at

https://project-trident.org/

You might try it in a virtual machine.

Ironically, Project Trident was the desktop part of TrueOS Desktop, which in turn used to be PC-BSD, a derivative of FreeBSD.

Stop spreading FUD. ".zfs/snapshot" has been working on Linux for years now. I don't know when you last used ZFS on Linux, but just because you haven't used ZoL for a while doesn't mean that the developers stopeed working on it.

Also, me and hundreds of other people have been booting off of ZFS on Linux for years. Your issue is most likely in your distro's initramfs setup or you must have botched the initramfs config yourself. If you're just used to FreeBSD, just stick to commenting about FreeBSD without maligning other operating systems.

Again, if it doesn't work, then it doesn't work; to users it doesn't matter _why_ - whether it's a problem with ZoL code itself, or with distro-provided initramfs. It's the end result that counts.

Well if it's working for everyone but a select few, then I'd argue the problem is with those select few and not the product.

> they are not doing zpool import -a(f)

That's an initramfs bug; the initramfs scripts are not actually supplied by the ZoL project. You should file a bug report against your distro's initramfs package.

That's part of the problem. From the user point of view it doesn't matter if the bug is due to initramfs, or the kernel, or ZoL, or whatever else. What matters is it doesn't work. With FreeBSD development model it's easier to get it to work, since it doesn't need to go through so many separate groups of people.

I am on fedora with added zol repository and fedora 30 doesn't supply any zfs modules or initramfs scripts. I had to do my scripts to verify that the modules are included and don't break my boot process. And it worked like a charm... for a while.

So... the bug is in your own scripts? I'm now thoroughly confused what your complaint is :)

> .zfs/snapshot still doesnt work

I've been using this as a server backup solution for over a year, I assure you zol snapshots work, including access via the .zfs directory.

I have ZFS images that I can't send from my freebsd server to my 16.04 server with the ZoL repo enabled. Given that it's my personal data I can't really submit until I narrow down to a minimal reproducing case, but yeah, there are bugs.

> Also the .zfs/snapshot still doesnt work.

What do you mean by this? I’m using ZoL and snapshots seem to be working fine.

zfs has a feature where you can `cd` to hidden .zfs folder (you wont see it by `ls`, imagine it like /procfs but hidden) on root of zfs filesystem (if you have tank/whatever mounted to /whatever this would be /whatever/.zfs) with some interesting content: within .zfs/snapshot you will get a list of snapshots for that filesystem with materialized state (!!!) of fs when the snapshot was taken. Imagine (instead of rollback the snapshot), just copying the original file(s) from there, with content from the time when snapshot was created.

This is imho, the killer feature of zfs, maybe matching only by VMS or DragonflyBSD hammer filesystems. They were/are both better at it (`undo`!) but zfs comes closely.

And it is broken for months now.

I haven't noticed that issue on Proxmox (been using zfs with it for approx. 6 months). Currently on zfs 0.8.4 (and I've done that previously).

Are you using a distro supplied zfs (potentially old) or rolling something more bleeding edge?

Just for any case, I would really love to solve this, I accept the fact that it is connected with upgrading the modules but this just is no reason for breaking backward compatibility.

root> zpool --version

zfs-0.8.4-1

zfs-kmod-0.8.4-1

root> ll /.zfs/snapshot

total 0

drwxrwxrwx 2 root root 2 jun 15 08:48 ./

drwxrwxrwx 1 root root 0 jun 10 07:53 ../

root> cat /etc/yum.repos.d/zfs.repo

[zfs]

name=ZFS on Linux for Fedora $releasever

baseurl=http://download.zfsonlinux.org/fedora/$releasever /$basearch/

enabled=1

metadata_expire=7d

gpgcheck=1

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-zfsonlinux

[zfs-source]

name=ZFS on Linux for Fedora $releasever - Source baseurl=http://download.zfsonlinux.org/fedora/$releasever/SRPMS/

enabled=0

gpgcheck=1

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-zfsonlinux

But nevermind, this is something that was working since zfs as root was brought into FreeBSD (and we are talking about FreeBSD not ZoL), never had issues about it.

> And it is broken for months now.

This guy speaks without knowing.

I just tried going in my .zfs/snapshot on my CentOS 7 system running kernel 3.10 and ZoL 0.8.3 and it's working. I can list snapshots and cat file off a snapshot.

After 10+ years of using zfs, I just "might" know something... ;) While your 1 year old versions of ZoL just "might" not prove anything.

if you had actually been using it during the last 1.5/2 years you would know it work.

otherwise you're just talking about stuff (zfs on gnu/linux) you know little about.

if you use zfs on freebsd then good for you, but that doesn't mean you can spread disinformation about zfs-on-linux.

btw: freebsd dropped its own implementation of zfs and is rebasing onto zfs-on-linux (from 2018: https://lists.freebsd.org/pipermail/freebsd-fs/2018-December...). that's how good zfs-on-linux is.

Just update your outdated ZoL to latest version. Than we can talk. And you might just agree.

I run ZFS on both Linux and FreeBSD. On Linux I compile from the latest releases. I’ve honestly not noticed any issues either.

Are you absolutely sure this isn’t something you’ve misconfigured yourself?

For what it’s worth, I do prefer FreeBSD over Linux but not not for any reasons relating to ZFS.

> CentOS 7 system running kernel 3.10

what the actual f*?

  tag name v3.10 (bc1b510b8979ecc322f8d930dde56658967b7355)
  tag date 2013-06-30 15:13:42 -0700

Even with stable fixes and CentOS distro sugar on top, running 3.10.x in 2020 feels batshit crazy. I always thought such reptilian kernels are only found on shitty embedded devices...

Wait until you find 2.6 (not many changes before 3.2 allegedly) and 2.4 kernels in embedded systems.

I'm well aware of 2.6 in embedded systems (and have to work with such systems T_T), I just didn't expect to see 3.10 in a system that also runs ZFS...

RHEL kernels are like that. They backport a ton of stuff and the major version number is of little relevance, but it doesn't change because they maintain a stable kABI.

By now the CentOS 7 kernel is probably closer to mainline 4.x and 5.x than the original 3.10

  $ cat /saspool/debian/master-buster/.zfs/snapshot/ci/etc/issue     
  Debian GNU/Linux 10 \n \l

ZFS 0.8.4 on Linux 5.4.43 — just as a data point in case you're trying to track this down. Both built from source, no distro patches.

(Yes my "tank" is named "pool"; /saspool/debian/master-buster is a template for my containers, "ci" is one of the containers.)

Works for me on Debian Unstable...

   sudo zpool --version
   zfs-0.8.4-1
   zfs-kmod-0.8.4-1

   uname -a
   Linux xxx 5.6.0-2-amd64 #1 SMP Debian 5.6.14-1 (2020-05-23) x86_64 GNU/Linux

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