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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

#41

Post by kobalsky »

nailer wrote: post #37
hnlmorg wrote: post #7

Earlier quoted context omitted.

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.

Not sure why you’d consider criticism of ZFS to he snark. Running any filesystem outside the mainline kernel is a bunch of extra effort and I’m sure as a ZFS user you’d know that. I’m not sure how ZFS could be “hugely successful” after two decades and still not in the Linux kernel.

> Running any filesystem outside the mainline kernel is a bunch of extra effort and I’m sure as a ZFS user you’d know that

zfs-dkms makes usage simple since openzfs backwards compatible down to 3.xx kernels. no need to mix match zfs with kernel versions anymore.

the only drawback is that you may not get to use the lastest kernel until openzfs mantainers give it the thumbs up (no 6.xx compatible release yet), but that's not "a bunch of extra effort".

and that's only a problem if you want to be in the bleeding edge. LTS kernel users wouldn't know about it.

> I’m not sure how ZFS could be “hugely successful” after two decades and still not in the Linux kernel.

"There is no way I can merge any of the ZFS efforts until I get an official letter from Oracle that is signed by their main legal counsel or preferably by Larry Ellison himself that says that yes, it's OK to do so and treat the end result as GPL'd" -Linus Torvalds

sound like a legal issue more than technical.

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

#42

Post by kobalsky »

ghaff wrote: post #28
WastingMyTime89 wrote: post #19

Earlier quoted context omitted.

> A) it took linux a long time to add support Linux has no support for ZFS. This is an out-of-tree patch set and therefor a no-go for most including myself. ZFS intentionally has a terrible license and is owned by Oracle. People are free to do what they want but I wish all the time wasted on it could have been put in something more interesting.

CDDL isn't an especially terrible license in isolation (it's basically Mozilla) but it is generally considered incompatible with GPL which, depending upon which set of 20 year old memories from ex-Sun employees you're inclined to believe, was more or less a deliberately nefarious state of affairs. Oracle owns most/all of the copyrights and Canonical was willing to take a calculated risk after, presumably, some back-c…

> I find it unfortunate that all the effort that has gone into ZFS as essentially a hobbyist copy-on-write filesystem didn't go into btrfs instead.

don't some BSDs and Linux share the same code base for ZFS?

Last I heard FreeBSD switched to ZfsOnLinux as upstream a few years ago before it was merged with OpenZFS.

IMO calling it a hobbyist fs is a bit unfair.

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

#43

Post by cmeacham98 »

ghaff wrote: post #28
WastingMyTime89 wrote: post #19

Earlier quoted context omitted.

> A) it took linux a long time to add support Linux has no support for ZFS. This is an out-of-tree patch set and therefor a no-go for most including myself. ZFS intentionally has a terrible license and is owned by Oracle. People are free to do what they want but I wish all the time wasted on it could have been put in something more interesting.

CDDL isn't an especially terrible license in isolation (it's basically Mozilla) but it is generally considered incompatible with GPL which, depending upon which set of 20 year old memories from ex-Sun employees you're inclined to believe, was more or less a deliberately nefarious state of affairs. Oracle owns most/all of the copyrights and Canonical was willing to take a calculated risk after, presumably, some back-c…

While the CDDL isn't a terrible license in a vacuum, it is (according to its author) _intentionally_ incompatible with the GPL (https://en.wikipedia.org/wiki/Common_Development_and_Distrib...).

This is, in my opinion, the most important part. It's not some unhappy accident that there are significant legal issues with ZFS and GPL-licenced Linux - that is (allegedly) by design.

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

#44

Post by Teknoman117 »

I've been kinda doing a similar thing with my Gentoo installation on btrfs.

The btrfs subvolumes are structured like this:

/$(hostname)/${environment}/@volume (e.g. @root, @home)

snapshots look like this:

/$(hostname)/${environment}/volume_$(date -u +%Y-%m-%d_%H-%M-00)

I have a few scripts "make-snapshots", "backup-snapshots", "update-shell", and "update-commit". make-snapshots creates readonly snapshots of my system, backup-snapshots does incremental backups of those to my NAS, update-shell creates a writable snapshot of @root as @root-update and drops you into a chroot environment. You can then run all the portage commands you want without fear of borking your current environment. Upon exit it checks whatever the /usr/src/linux symlink points to, copies the associated vmlinuz and initramfs images to the EFI partition, and creates/updates a boot entry in rEFInd. You can then boot either into your previous version or the update version. Once you're satisfied that your new environment works, you run "update-commit" which deletes the @root subvolume and replaces it with your current @root-update subvolume.

A change I've been considering is to drop the concept of having a @root subvolume at all. Current implementation requires two reboots: one to get from @root to @root-update, where (if it's good) you delete @root and make a writable snapshot of @root-update as @root. The second reboot is to get onto (the new) @root. An alternative might be to include the date/version in the name of the writable snapshots as well. "committing" the update would just mean setting the current booted subvolume as the "head". Future snapshots/updates will be made from that subvolume. No need for a reboot because you're currently on it with everything mounted correctly. Any writable subvolumes older than "head" would be cleaned up upon booting "head".

Could even go a step further and add something to my initramfs where if you try to boot a version where the writable subvolume has been deleted, it would make a temporary writable subvolume for it from the snapshot.

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

#45

Post by ghaff »

cmeacham98 wrote: post #43
ghaff wrote: post #28

Earlier quoted context omitted.

CDDL isn't an especially terrible license in isolation (it's basically Mozilla) but it is generally considered incompatible with GPL which, depending upon which set of 20 year old memories from ex-Sun employees you're inclined to believe, was more or less a deliberately nefarious state of affairs. Oracle owns most/all of the copyrights and Canonical was willing to take a calculated risk after, presumably, some back-c…

While the CDDL isn't a terrible license in a vacuum, it is (according to its author) _intentionally_ incompatible with the GPL ( https://en.wikipedia.org/wiki/Common_Development_and_Distrib... ). This is, in my opinion, the most important part. It's not some unhappy accident that there are significant legal issues with ZFS and GPL-licenced Linux - that is (allegedly) by design.

As that section says, there is (at least for public consumption) disagreement among then-Sun employees as to what the intent and beliefs were at the time.

I know all those folks to greater or lesser degrees and Sun was a client of mine as an analyst. There were certainly a lot of conflicting motivations and concerns concerning Solaris and Linux.

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

#46

Post by yakak »

kobalsky wrote: post #42
ghaff wrote: post #28

Earlier quoted context omitted.

CDDL isn't an especially terrible license in isolation (it's basically Mozilla) but it is generally considered incompatible with GPL which, depending upon which set of 20 year old memories from ex-Sun employees you're inclined to believe, was more or less a deliberately nefarious state of affairs. Oracle owns most/all of the copyrights and Canonical was willing to take a calculated risk after, presumably, some back-c…

> I find it unfortunate that all the effort that has gone into ZFS as essentially a hobbyist copy-on-write filesystem didn't go into btrfs instead. don't some BSDs and Linux share the same code base for ZFS? Last I heard FreeBSD switched to ZfsOnLinux as upstream a few years ago before it was merged with OpenZFS. IMO calling it a hobbyist fs is a bit unfair.

Being called hobbyist software derisively by the Linux community is like being knighted, I assume.

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

#47

Post by hnlmorg »

nailer wrote: post #37
hnlmorg wrote: post #7

Earlier quoted context omitted.

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.

Not sure why you’d consider criticism of ZFS to he snark. Running any filesystem outside the mainline kernel is a bunch of extra effort and I’m sure as a ZFS user you’d know that. I’m not sure how ZFS could be “hugely successful” after two decades and still not in the Linux kernel.

Linux users are constantly using drivers outside of the mainline kernel. Whether it’s graphics cards, radio drivers (things have gotten better in that regard but Bluetooth is support is still terrible) or FUSE file systems.

The difference with ZFS is that the code is kernel-ready but there’s just some licensing worries (understandable ones) that stop it from being mainlined.

I’ve been running ZFS on Ubuntu Server for several years now and frankly ZFS is the only part of that entire system that doesn’t suck (in my opinion). I’d switch back to FreeBSD in a heartbeat if I didn’t need Docker support but credit where credit is due, Ubuntu’s ZFS support has been really good.

Edit: just to add, I’ve got nothing against anyone who does enjoy Ubuntu Server. It’s just not a Linux distro I personally have much fondness for.

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

#48

Post by ninefathom »

nortonham wrote: post #36
ninefathom wrote: post #16

I'm glad to see interest in this functionality taking off in Linux-land. I think there are one or two other projects with similar goals (i.e. implementing BE selection on Linux) and it might be time for me to do a side-by-side. This capability was something of which the lack on Linux has long puzzled me. Solaris actually implemented a very early incarnation of this ability (called "live upgrades" at the time from its…

what do you use OpenIndiana for? >This capability was something of which the lack on Linux has long puzzled me. Agreed. I recently tried out OI "hipster" and the way boot environments are integrated into caja (the file manager) with Time Slider was so smooth it got me thinking why something like it wasn't more popular in linux.

> what do you use OpenIndiana for?

I find that it's a good fit for quite a few things, but if you're looking for a specific example: clustered Java application stacks, like ELK or Hadoop.

Zones, crossbow networking, SMF, and ZFS w/ BEs all working seamlessly together is a fantastic combination for easy-button admin of low- or zero-downtime clustered applications.

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

#49

Post by yjftsjthsd-h »

szanni wrote: post #40
vermaden wrote: post #38

I still wait for ANY Linux distro that would have installer that would allow you to install Linux with Root on ZFS and with ZFSBootMenu (or any other ZFS Boot Environments tool) ...

I would love to see that too, but believe this is rather unlikely for any major Linux distro. Why? Because there is no guarantee the required kernel symbols will stay available. This has for example happened with the linux-rt branch that decided to change the license of some of the exported kernel symbols to GPL, which prevents the ZFS module from compiling. As far as I can tell, the kernel developers make sure to no…

> I would love to see that too, but believe this is rather unlikely for any major Linux distro. Why? Because there is no guarantee the required kernel symbols will stay available.

Er, Ubuntu already supports ZFS root out of the box in the default installer; why would ZBM be any harder to support than that?

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

#50

Post by yjftsjthsd-h »

dazzawazza wrote: post #2

Always good to see Linux being inspired by FreeBSD.

I mean, at that point it's really inspired by Open/Solaris, right? It may have been spread to FreeBSD before Linux, but it didn't start there either. (Excellent to see wider use either way, of course.)
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