Linked by Thom Holwerda on Fri 20th Apr 2007 19:05 UTC, submitted by Rahul
Linux A recent discussion on the lkml examined the possibility of a Linux implementation of Sun's ZFS. It was pointed out that the file system is released under the GPL-incompatible CDDL, and that Sun has filed numerous patents to prevent ZFS from being reverse engineered. Max Yudin pointed out, "according to Jeff Bonwick's blog Sun issued 56 patents on ZFS, but I have no idea what they patented. Sorry, binary compatible ZFS reimplementation with GPL license might not be legal."
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Use FUSE
by Alexey Technologov on Fri 20th Apr 2007 19:14 UTC
Alexey Technologov
Member since:
2007-03-16

Actually, I don't see any problem here; Instead of building a kernel driver for ZFS, build FUSE driver. It will solve the license issue, *and* will be available for multiple OSes including Linux, Mac OS X and BSD UNIX.

Reply Score: 2

RE: Use FUSE
by AlexandreAM on Fri 20th Apr 2007 19:22 UTC in reply to "Use FUSE"
AlexandreAM Member since:
2006-02-06

First of all a disclaimer: This is not an attempt to bash the parent post, but a genuine question.

How would it be that building a FUSE driver would solve the patents issue ?

Reply Score: 5

RE[2]: Use FUSE
by anevilyak on Fri 20th Apr 2007 19:29 UTC in reply to "RE: Use FUSE"
anevilyak Member since:
2005-09-14

Because a FUSE driver wouldn't have to link to the GPLed kernel and would consequently not present a license conflict. Also, there was already work in progress on a FUSE ZFS impl for last year's GSoC, though I have no idea how far that progressed in the end.

Update: Err, missed the actual point. The FUSE driver could, due to the lack of license issues, use the actual ZFS code, which would prevent the patent issue from cropping up.

Edited 2007-04-20 19:31 UTC

Reply Score: 5

RE: Use FUSE
by phoenix on Fri 20th Apr 2007 20:00 UTC in reply to "Use FUSE"
phoenix Member since:
2005-07-11

*and* will be available for multiple OSes including Linux, Mac OS X and BSD UNIX.

It will be available on MacOS X (will be part of Leopard), and is already available on FreeBSD -CURRENT (will be part of 7.0).

Linux is the only one not in the ZFS party. ;)

Reply Score: 4

RE[2]: Use FUSE
by Duffman on Fri 20th Apr 2007 20:38 UTC in reply to "RE: Use FUSE"
Duffman Member since:
2005-11-23

Hehe, owned by their licence.

Reply Score: 2

RE[3]: Use FUSE
by sbergman27 on Fri 20th Apr 2007 22:10 UTC in reply to "RE[2]: Use FUSE"
sbergman27 Member since:
2005-07-24

"""
Hehe, owned by their licence.
"""

Well. I'm a Linux advocate. And I am partial to the GPL, despite what a pain in the ass it can, at times, be.

BUT... I can agree that it is a good thing for GPL advocates to occasionally get hoist by their own petard.

There is a lot of unfairness going on in the form of "we can take your code but you can't take ours" and it is mostly in the direction of BSD Project -> GPL Project.

You can actually substitute many permissive licenses for "BSD" in the statement above.

It's good for GPL advocates to, at least occasionally, see that the GPL has thorns as well as teeth.

It is the inflexible nature of the GPL, more than the terms of the CDDL, that are denying Linux ZFS.

Then again, by Linux standards, ZFS is, in Andrew Morton's words, a "rampant layering violation".

Beyond the licensing issues, I think we'd be more likely to see Reiser4 merged than ZFS, without some major philosophical reworking of the design.

Edited 2007-04-20 22:18

Reply Score: 5

RE[2]: Use FUSE
by AlexandreAM on Fri 20th Apr 2007 20:40 UTC in reply to "RE: Use FUSE"
AlexandreAM Member since:
2006-02-06

How is it that Mac OS X and FreeBSD overcame the patents problem ? Wouldn't it be possible for Linux to do things the same way ?

Do they use binary compatible reimplementations of the FS ? If so I guess they're all in the same ship with those patents problems.

(I really doesn't know much about ZFS history and implementations, so please excuse if the answers to those questions are obvious).

Reply Score: 1

RE[3]: Use FUSE
by nathanw on Fri 20th Apr 2007 20:53 UTC in reply to "RE[2]: Use FUSE"
nathanw Member since:
2006-11-05

They both use Sun's code. Presumably Apple worked something out with them, and the 2-clause BSD license is not incompatible with the CDDL, so there's no problem with FreeBSD. The issue with Linux is that Sun's license and Linux's are both restrictive, but in different ways. Mixing Sun's work with more permissively licensed code is not a problem.

Reply Score: 5

RE[4]: Use FUSE
by whartung on Fri 20th Apr 2007 21:00 UTC in reply to "RE[3]: Use FUSE"
whartung Member since:
2005-07-06

The CDDL that ZFS is under has an explicit patent grant, so if you can keep the CDDL license, then you don't have a patent problem.

As mentioned, BSD doesn't really have this issue at all. CDDL is also, like MPL, a file based licensed. So, Apple is obligated to only return any changes they made to ZFS files, but aren't under any obligation to return their entire OS simply because they integrate ZFS.

Beyond perhaps some behind the scenes contracting between Apple and Sun for technical support, there need be otherwise no formal relationship between the companies.

Reply Score: 5

v RE[2]: Use FUSE
by tomcat on Fri 20th Apr 2007 21:36 UTC in reply to "RE: Use FUSE"
v RE[3]: Use FUSE
by tomcat on Fri 20th Apr 2007 22:38 UTC in reply to "RE[2]: Use FUSE"
RE: Use FUSE
by Mathman on Sat 21st Apr 2007 01:00 UTC in reply to "Use FUSE"
Mathman Member since:
2005-07-08

Ha, already under way:
http://www.wizy.org/wiki/ZFS_on_FUSE

Reply Score: 2

RE: Use FUSE
by victor on Mon 23rd Apr 2007 14:20 UTC in reply to "Use FUSE"
victor Member since:
2006-09-13

I see a huge problem, there's no way that I'm going to run a userspace filesystem on a machine in production.

And when it comes to my desktop, I couldn't care less about the filesystem, ext3 and lvm is more than flexible enough.

Reply Score: 1

FUSE
by Abaddon on Fri 20th Apr 2007 19:20 UTC
Abaddon
Member since:
2006-06-23

And it will operate much slower.

(BTW. It's supported by FreeBSD already).

Edited 2007-04-20 19:21

Reply Score: 3

RE: FUSE
by tyrione on Fri 20th Apr 2007 21:02 UTC in reply to "FUSE"
tyrione Member since:
2005-11-21

I would hope FreeBSD supports ZFS, in matters of legality, seeing as how FreeBSD isn't underwritten with the GPL as it's licensing scheme.

Reply Score: 2

RE[2]: FUSE
by phoenix on Fri 20th Apr 2007 21:36 UTC in reply to "RE: FUSE"
phoenix Member since:
2005-07-11

FreeBSD even has support for Sun's DTrace, although it can't be included with the GENERIC kernel by default due to licensing issues with a few bits (mainly headers, I believe).

Reply Score: 4

Compatibility of Free licenses
by Luis on Fri 20th Apr 2007 19:31 UTC
Luis
Member since:
2006-04-28

Sooner or later the issue of compatibility among Free licenses must be addressed. It's a very sad situation when two FOSS projects can't use each other's code because of license incompatibilities.

Especially the copyleft licenses lke the GPL should include a compatibility clause so that they allow to merge for example GPL code with any other Free license explicitly approved in the GPL. That way, the GPL code would remain GPL'ed, while the code under the other (now incompatible) license would remain under its own license.

After all, they're all Free and Open Source projects. And why not ship a program whose code is under 3 or 4 different licenses? Any Linux (or BSD) distribution ships with many programs under many different Free licenses and it's not a problem. So one single program with many Free licenses should be possible too.

I wish the GPLv3 would consider such clause, but up to now I haven't heard anything about it.

Edited 2007-04-20 19:34

Reply Score: 4

RE: Compatibility of Free licenses
by phoenix on Fri 20th Apr 2007 20:02 UTC in reply to "Compatibility of Free licenses"
phoenix Member since:
2005-07-11

That would defeat the "all software must be free -- by which we mean GPL'd" mantra. ;)

Reply Score: 3

Kroc Member since:
2005-11-10

The FSF want to hold the reigns. If there's going to be any licence compatibility, they want to be the ones who decide, not the actual project owners; and the GPL3 is even worse. I suspect when the first GPL3 violation occurs, it'll be laughed out of court for it's almost EULA-like unenforceableness (yes that is a real word; that I just made up).

Reply Score: 5

Ford Prefect Member since:
2006-01-16

Backup your claims, please.

Reply Score: 4

Kroc Member since:
2005-11-10

I've said before - the FSF trying to step above the patent system is as bad as Microsoft using it. That is my stance on it and I shall refrain from detailing further to save a three-hundred long thread of disagreements.

Reply Score: 3

Ford Prefect Member since:
2006-01-16

Your first post claimed the FSF wants to decide upon license compatibilities, not step above patent systems.

First, the FSF doesn't decide at any stage which licenses are compatible. The license "decides". If a project takes license X, it made this decision itself!

Second, the GPLv3 isn't in any case more restrictive about compatibility than the GPLv2.


The kernel devs could have chosen LGPL as their license. They could also have chosen then, that parts of the kernel won't be licensed under GPL, but some other license, like CDDL. I doubt the kernel devs would ever want to do this step. So the only possibility for the kernel devs - self chosen! - to get code into their kernel, is to
a) rewrite it
b) having a license on it (like BSD) which allows to re-publish under GPL

Whereas, a) could not be legal, as it would violate SUN's patents.


Again, the FSF has to do _nothing_ with this issue. It's just the kernel developers who don't want to incorporate CDDL code. Which is totally sane to me.

Edited 2007-04-21 00:14

Reply Score: 2

antik Member since:
2006-05-19

b) having a license on it (like BSD) which allows to re-publish under GPL

THAT'S a STRICT VIOLATION OF BSDL!

Read here: http://www.opensource.org/licenses/bsd-license.php

All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
* Neither the name of the <ORGANIZATION> nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.


Who was that idiot who thought that he can relicense BSDL as GPL?

Reply Score: 3

Ford Prefect Member since:
2006-01-16

You can take BSDL code and give it to others within another license. This is what Microsoft does, Apple does, and some open source projects do, too.

The other license just has to include the BSD licence terms in that case.

Reply Score: 5

Spellcheck Member since:
2007-01-20

Thank you for the response. The presence of the link gave me a good laugh.

Reply Score: 1

SomeGuy Member since:
2006-03-20

Right, and this is why the FSF puts a list of free software licenses and their compatibility with the GPL here: http://www.gnu.org/licenses/license-list.html#SoftwareLicenses

All of these licenses are what they consider free. Not all are copyleft, of course.

Reply Score: 2

RE: Compatibility of Free licenses
by abraxas on Sun 22nd Apr 2007 11:35 UTC in reply to "Compatibility of Free licenses"
abraxas Member since:
2005-07-07

Especially the copyleft licenses lke the GPL should include a compatibility clause so that they allow to merge for example GPL code with any other Free license explicitly approved in the GPL. That way, the GPL code would remain GPL'ed, while the code under the other (now incompatible) license would remain under its own license.

Go to http://www.gnu.org to find out why this is a terrible idea. Basically you are giving no incentive for GPL software to be developed. No company working on Linux is going to release their code under the GPL if they don't have to that's why the GPL forces companies and everyone else to.

Reply Score: 2

you're kidding, right?
by tom9285 on Sun 22nd Apr 2007 17:39 UTC in reply to "Compatibility of Free licenses"
tom9285 Member since:
2007-04-22

Why do you think ZFS comes under a license that's incompatible with the Linux kernel? Sun could have chosen any license they wanted, and they deliberately picked one that was incompatible with the Linux kernel.

It's Sun's right to do that, just understand why: they want to replace the Linux kernel with a kernel whose development they control.

And, no, they are not all "Free and Open Source projects". BSD are open source projects but are not Free Software. ZFS (and Solaris) may be shipping under an open source license, but they are not run like open source projects.

There are reasons all these projects have difference licenses, and they will not be made compatible because lots of people don't want it (and that's a good thing as far as I'm concerned).

Reply Score: 2

RE: you're kidding, right?
by binarycrusader on Wed 25th Apr 2007 04:29 UTC in reply to "you're kidding, right?"
binarycrusader Member since:
2005-07-06

Why do you think ZFS comes under a license that's incompatible with the Linux kernel? Sun could have chosen any license they wanted, and they deliberately picked one that was incompatible with the Linux kernel.


Care to back up those claims with evidence? Sorry, but those are just lies. Flat out lies.

It's Sun's right to do that, just understand why: they want to replace the Linux kernel with a kernel whose development they control.


Conspiracy theorists unite!

Seriously, you don't have anything factual to back up these claims. You have nothing but wild speculation at best and the lies of another individual.

Reply Score: 2

Ask Sun
by werfu on Fri 20th Apr 2007 20:10 UTC
werfu
Member since:
2005-09-15

why not ask Sun directly? It's their code after all, they can modify its licensing as they wish. Just ask them to roll out a GPL-compatible licenced version. why reverse engineer when you can simply ask for it? I mean, Sun is not evil IMHO and would certainly agree to find a mean for its ZFS to be redistributed. After all, more ZFS users, especially on servers, mean more potential clients for Sun's Solaris.

Reply Score: 2

RE: Ask Sun
by Duffman on Fri 20th Apr 2007 20:44 UTC in reply to "Ask Sun"
Duffman Member since:
2005-11-23

lol, it's exactly the contrary.
The more linux will get Solaris features, the less they will have potential clients for Solaris.

Fortunately for Sun, Linux can not get Solaris features.

Reply Score: 2

RE[2]: Ask Sun
by flanque on Fri 20th Apr 2007 22:57 UTC in reply to "RE: Ask Sun"
flanque Member since:
2005-12-15

Maybe. Sun offer end-to-end solutions for systems, from the hardware, software, testing, development, support and training. I know redhat offers this too, but they don't control the hardware like Sun can. Plus, in my view, Sun are more reliable than RedHat.

Reply Score: 2

RE[3]: Ask Sun
by kaiwai on Sat 21st Apr 2007 09:48 UTC in reply to "RE[2]: Ask Sun"
kaiwai Member since:
2005-07-06

Maybe. Sun offer end-to-end solutions for systems, from the hardware, software, testing, development, support and training. I know redhat offers this too, but they don't control the hardware like Sun can. Plus, in my view, Sun are more reliable than RedHat.


True, and if you have a look at the latest acquisitions - StorageTek which gets them into the IBM houses which rely on large tape libraries. Tarantella which brings together Windows, UNIX's of various flavours and mainframe access, Sun can offer a complete solution, like you said.

It isn't just about the control, but to make a loss off the hardware and make it up somewhere else. Rather than worrying about making a profit on each component sold, they make a profit on the whole kit sold at the same time. When you go for a Red Hat solution, everyone is gotta take their cut.

Dell sells you the server, they want to take a cut. EMC for the storage machine, then you'll need to grab some storage software, so you'll grab it from them. Then you'll need a company to deploy it, so you bring in someone like IBM global services or EDS.

With each cut taken by each company along the process of getting what you need, each must take a cut in terms of a profit; and what do you gain out of it? a frankenstein network from various companies who will simultaneous point the finger at each other when the shit hits the fan.

Reply Score: 5

v RE[2]: Ask Sun
by tom9285 on Sun 22nd Apr 2007 17:41 UTC in reply to "RE: Ask Sun"
RE[3]: Ask Sun
by Arun on Sun 22nd Apr 2007 18:23 UTC in reply to "RE[2]: Ask Sun"
Arun Member since:
2005-07-07

Fortunately for Linux, many Solaris features are probably a bad idea anyway. For example, volume management and the file system probably shouldn't be merged.

Care to explain why? I am starting to suspect sour grapes. Every pro linux person seems to regurgitate the same argument but with no reasoning about why.

Edited 2007-04-22 18:40

Reply Score: 4

ZFS, good ideas...
by bnolsen on Fri 20th Apr 2007 20:36 UTC
bnolsen
Member since:
2006-01-06

I like the ideas behind ZFS.

I think the linux kernel folks could likely do something like zfs with one of the file systems by integrating it more with the LVM layer.

It's nice sun has this code there and available, but I think for the linux community the long term bang for the buck will be from new thinking and refactoring from what ZFS brings.

Reply Score: 2

RE: ZFS, good ideas...
by phoenix on Fri 20th Apr 2007 21:16 UTC in reply to "ZFS, good ideas..."
phoenix Member since:
2005-07-11

It's nice sun has this code there and available, but I think for the linux community the long term bang for the buck will be from new thinking and refactoring from what ZFS brings.

Also known as "Not Invented Here" syndrome, which is what the vast majority of Linux kernel developers have. Everyone thinks they can do it better, so everything gets redone, over and over and over again. Doesn't matter that some other OS has ready, reliable code. The Linux devs can do it better.

Sun's DTrace and ZFS are just two examples of this, although the GPL plays a large part in these.

Reply Score: 5

RE[2]: ZFS, good ideas...
by w00dst0ck on Fri 20th Apr 2007 22:50 UTC in reply to "RE: ZFS, good ideas..."
w00dst0ck Member since:
2006-02-01

Would you think that if Linux could implement DTrace and ZFS that they wouldn't do it their way?

FreeBSD for instance (and yes I understand the license differences please spare me) seems to not want to duplicate work that already works, so they just integrate it into their OS, which I think is the right way to go about it. I believe that Linux would do the same if they could, legally. But then again it seems to be a per-distro thing these days (Eg: Ubuntu's upstart... i understand that they want to improve things, but why make something completely different from the standard working implementation, but that's not related really...)

Overall from what I hear (haven't had a chance to test it out myself) but ZFS is pretty impressive. I wish I had some links to some numbers, but google is friend ;) .

Reply Score: 3

RE[2]: ZFS, good ideas...
by dylansmrjones on Fri 20th Apr 2007 23:38 UTC in reply to "RE: ZFS, good ideas..."
dylansmrjones Member since:
2005-10-02

AFAIK there is no NIH-syndrome among Linux devs. It's a lie spread by opponents. Linux devs have more than once included technology from outside. More often than not it has been rewritten but this is due to techical reasons and not because of NIH-syndrome.

Reply Score: 3

RE[3]: ZFS, good ideas...
by Cloudy on Sat 21st Apr 2007 19:28 UTC in reply to "RE[2]: ZFS, good ideas..."
Cloudy Member since:
2006-02-15

AFAIK there is no NIH-syndrome among Linux devs. It's a lie spread by opponents.


As someone who is a Linux developer, let me disabuse you of that notion.

Like many social groups, the Linux developer community has a social pecking order. Some of the people at the top, most notably Linus himself, do not suffer from NIH syndrome, but there are certain parts of the kernel in which there are very bad cases of NIH.

Examine the history of power management, file systems, usb, scsi, kernel objects, and a few other things and you'll easily find the NIH.

Reply Score: 4

RE[3]: ZFS, good ideas...
by sbergman27 on Sat 21st Apr 2007 21:04 UTC in reply to "RE[2]: ZFS, good ideas..."
sbergman27 Member since:
2005-07-24

"""
AFAIK there is no NIH-syndrome among Linux devs. It's a lie spread by opponents.
"""

I think it more a misperception by people who didn't get their favorite feature included.

As users, we have the luxury of seeing features, say Reiser4, saying "Oooo! Shiny!" and petitioning for the code's inclusion. The people who actually have to integrate it and maintain it must take a more critical look.

Is the code maintainable? Does it contain an ugly compatibility layer like XFS? Does it try to replace whole layers of Linux, like VFS, with its own version running in parallel, as Reiser4 does?

If they say "no" to a set of patches, the fans of the excluded features immediately conclude that NIH is at work.

Earlier on, Linux had few enough features that some patches got a free ride. The kernel devs are free to be more critical in their evaluations today.

For example, I suspect that XFS, if presented for inclusion today, would have to live out of tree. The impedance mismatch would simply be too great to accept now that journaling Linux FSes are plentiful, and at least some of the aura of mystique that surrounds XFS has worn off, due to the passage of time, and the realization by users of just how fragile XFS really is.

One of the most important requirements of a maintainer of a large and popular project is the ability to say "no". But saying "no" is also a guarantee that some people are going to accuse him of having an NIH attitude.

Edited 2007-04-21 21:08

Reply Score: 4

RE[4]: ZFS, good ideas...
by segedunum on Sat 21st Apr 2007 21:41 UTC in reply to "RE[3]: ZFS, good ideas..."
segedunum Member since:
2005-07-06

As users, we have the luxury of seeing features, say Reiser4, saying "Oooo! Shiny!" and petitioning for the code's inclusion. The people who actually have to integrate it and maintain it must take a more critical look.

Which is why no ZFS implementation would actually get in. It crosses so many layers that already exist in the kernel itself, it's even worse than Reiser4.

Reply Score: 2

RE[2]: ZFS, good ideas...
by segedunum on Sat 21st Apr 2007 09:25 UTC in reply to "RE: ZFS, good ideas..."
segedunum Member since:
2005-07-06

Also known as "Not Invented Here" syndrome, which is what the vast majority of Linux kernel developers have.

Go and ask Sun about that, because they explicitly put the whole thing under a license that was deliberately GPL incompatible. There has been a lot of code that has made it into the Linux kernel from outside, as long as licenses permit.

I'm intrigued by the whole patent thing though, because I wonder how this tallies with Sun's new found GPL love.

Reply Score: 3

RE[3]: ZFS, good ideas...
by comay on Sat 21st Apr 2007 22:32 UTC in reply to "RE[2]: ZFS, good ideas..."
comay Member since:
2005-09-16

I don't know whether its ignorance on your part or if you have an agenda but please stop repeating the mistruth that CDDL was deliberately made incompatible with the GPL. Sun examines a lot of licenses for OpenSolaris, including the GPL. Please see Simon Phipps blog postings on this subject as well as the mailing post entry

http://www.opensolaris.org/jive/message.jspa?messageID=55008#55008

Reply Score: 3

RE[4]: ZFS, good ideas...
by sbergman27 on Sat 21st Apr 2007 23:00 UTC in reply to "RE[3]: ZFS, good ideas..."
sbergman27 Member since:
2005-07-24

"""
please stop repeating the mistruth that CDDL was deliberately made incompatible with the GPL.
"""

CDDL was deliberately made incompatible with Linux. That is a slightly different statement. And the post you point to actually supports that viewpoint by stating that they could not wait for GPLv3 (which would have met the criterion of being Linux incompatible).

At any rate, if it comes down to trusting Danese Cooper or Simon Phipps, I'd pick Cooper any day of the week.

Edited 2007-04-21 23:01

Reply Score: 2

ZFS is not "all that"
by Milo_Hoffman on Fri 20th Apr 2007 21:08 UTC
Milo_Hoffman
Member since:
2005-07-06

Frankly, ZFS is not really all that new.

Its simply a decent volume manager and a good filesystem with some glue making it a little nice to use.

Linux has had a pretty good volume manager(LVM based on HPUX's excellent design) for years now, WAY before Solaris did, and fixes what was starting to make SUN look embarissing in the industry for not having one yet in their OS compared to HPUX, AIX, Linux etc having them for many years already.

Before ZFS, Solaris was the lamest UNIX known to man in its native storage abilities.


And MANY of the stuff that ZFS does with raid etc is really not needed in any shop that has REAL storage arrays.

Reply Score: 1

RE: ZFS is not "all that"
by WereCatf on Fri 20th Apr 2007 21:35 UTC in reply to "ZFS is not "all that""
WereCatf Member since:
2006-02-15

Err, you apparently don't have a clue about what you're saying..ZFS is a lot more than a volume manager or a plain filesystem. First of all, it's a completely self-healing atomic system, it's consisted of pools, etc etc etc.. Does LVM protect you from silent corruption of filesystems? Nope, it doesn't. Why? Because it's just a volume manager..So that's already more than enough of a reason to use ZFS IMHO. I suggest you read a little bit more before you spread FUD

Reply Score: 5

RE: ZFS is not "all that"
by Robert Escue on Fri 20th Apr 2007 22:24 UTC in reply to "ZFS is not "all that""
Robert Escue Member since:
2005-07-08

And I take it you have never used Veritas Volume Manager or Veritas File System (VxVm and VxFS). There is a lot more to managing large storage arrays than laying down a filesystem on a large hardware based RAID 5 array.

Does HP's or Linux LVM support snapshot capabilities? That alone is enough for me to use ZFS over a stock UFS filesystem. And the ability to add storage to a pool dynamically for immediate use rocks. And this is not limited to hard disks, check out this video of some Sun engineers using ZFS on USB memory sticks:

http://video.google.com/videoplay?docid=8100808442979626078

I somehow don't think that either HP's or Linux LVM solutions can reproduce what Sun does with ZFS.

Edited 2007-04-20 22:25

Reply Score: 5

RE[2]: ZFS is not "all that"
by sukru on Sat 21st Apr 2007 07:29 UTC in reply to "RE: ZFS is not "all that""
sukru Member since:
2006-11-19

And I take it you have never used Veritas Volume Manager or Veritas File System (VxVm and VxFS). There is a lot more to managing large storage arrays than laying down a filesystem on a large hardware based RAID 5 array.

Does HP's or Linux LVM support snapshot capabilities? That alone is enough for me to use ZFS over a stock UFS filesystem. And the ability to add storage to a pool dynamically for immediate use rocks. And this is not limited to hard disks, check out this video of some Sun engineers using ZFS on USB memory sticks:


ZFS has many qualities that LVM (or Veritas) does not provide. Yet what you've mentioned can already be done.

* LVM2 does support snapshots (and we're actively using them for backup purposes)
* LVM2 does allow dynamically adding (or removing) storage items to the pool (and enlarging ext3 filesystems on the fly, but don't know about online shrinking).
* LVM2 does indeed support any block device (since it's based on device-mapper), yes it does USB disks too.

But as I said there are many areas (like online self healing) that ZFS can but LVM cannot, however your choice of features is already done.

Edited 2007-04-21 07:32

Reply Score: 4

RE[3]: ZFS is not "all that"
by sbergman27 on Sat 21st Apr 2007 15:19 UTC in reply to "RE[2]: ZFS is not "all that""
sbergman27 Member since:
2005-07-24

So far as I know, online shrinking if ext3 filesystems is not supported.

And you are correct that the Linux stack does not have checksumming and self-healing.

For the rest of it, Linux could really steal Sun's thunder simply by improving the admin tools.

dm/lvm/ext3 have all these capabilities, but the admin has to explicitly worry about partitioning the drives, marking them as physical volumes, adding them to the pool, resizing the logical volume, and resizing the filesystem.

It's even more complicated to remove storage from the pool.

If we could just get our act together with regards to admin tools, ZFS would not get all the Ooos! and Ahhhs! that it does.

Arguably, Sun's decision to dump all the capabilities into the filesystem layer itself made writing the admin tools easier for them. But there is no reason that things could not be just as simple and straightforward for Linux admins.

Reply Score: 3

RE[2]: ZFS is not "all that"
by segedunum on Sat 21st Apr 2007 10:28 UTC in reply to "RE: ZFS is not "all that""
segedunum Member since:
2005-07-06

And I take it you have never used Veritas Volume Manager or Veritas File System (VxVm and VxFS). There is a lot more to managing large storage arrays than laying down a filesystem on a large hardware based RAID 5 array.

You've answered your own question really. ZFS is certainly a step forward for those running Sun systems and wanting large scale storage options, because let's face it, what went before was pretty non-existant and quite woeful. That's where ZFS' home really is - large storage arrays.

For those in the Linux and other areas of the Unix worlds, they have had the option of keeping their existing filesystems and using LVM or EVMS with a combination of RAID, ATA-over-ethernet, iSCSI (has its problems) etc. or products like those from Veritas. Those doing it are...........already doing it, and ZFS has slipped their consciousness. All Sun is doing is trying to stop existing Solaris using people from jumping ship.

Does HP's or Linux LVM support snapshot capabilities?

LVM certainly does, and has been widely known about for years. You do know this, right?

That alone is enough for me to use ZFS over a stock UFS filesystem.

Snapshots is enough on its own for you to use ZFS? Wow. Welcome to 2007.

I also don't see what UFS has got to do with it, because volume management is logically removed from the filesystem itself - which is why Andrew Morton complained about ZFS as a layering violation. You could reasonably install a UFS filesystem on a LVM volume and make it work. There's no reason to create a new uber filesystem just to do that and pretend it's something new and cool.

I somehow don't think that either HP's or Linux LVM solutions can reproduce what Sun does with ZFS.

Wow. Chaining a bunch of separate storage volumes together to create more storage space - a bunch of USB sticks in this case. Never been done before.

You can use Linux LVM, EVMS and/or RAID (whether that be software or hardware) and your normal filesystem to do exactly that. You can do LVM over a network for crying out loud. At a higher level, that's what GFS is about. Goodness, you can even do ATA-over-ethernet. If they'd done that over a network hub I might have found that moderately interesting. A nice and usable GUI representation, overview and interface would have been nice as well. Lame. I also don't get the scrambling of USB sticks into a random order at the end of the video, because...........that's what a RAID array pieces together.

It's a good example of why Andrew Morton thinks that ZFS is a layering violation, because much of what ZFS does has absolutely nothing to do with file storage itself or a filesystem. Sun pretending that it is just daft.

You're seriously telling me you don't think any of that can be done on a Linux system?

Personally, I think the most interesting part of that video was using USB flash drives as storage, because I think that's where the next advance in storage will come from. Widespread, cheap and large flash drive arrays. That's the only way reliability and availability will truly increase - better devices themselves.

Edited 2007-04-21 10:33

Reply Score: 5

RE[3]: ZFS is not "all that"
by Robert Escue on Sat 21st Apr 2007 17:26 UTC in reply to "RE[2]: ZFS is not "all that""
Robert Escue Member since:
2005-07-08

Actually, no I didn't. The vast majority of the Linux servers we use do not have large storage arrays attached to them, mostly local storage (DL385/585 internal disks), and they are set up using the hardware RAID controllers. So we have never really looked at using LVM or LVM snapshots. And based on this discussion, I really don't know whether I would want to:

http://lwn.net/Articles/226796/

Reply Score: 2

RE[4]: ZFS is not "all that"
by segedunum on Sat 21st Apr 2007 21:59 UTC in reply to "RE[3]: ZFS is not "all that""
segedunum Member since:
2005-07-06

and they are set up using the hardware RAID controllers. So we have never really looked at using LVM or LVM snapshots. And based on this discussion, I really don't know whether I would want to

*shrugs shoulders*

I don't really see why you wouldn't use LVM, even with hardware RAID. They're different layers in the system and have different and complementary uses.

Reply Score: 2

RE[5]: ZFS is not "all that"
by Robert Escue on Sun 22nd Apr 2007 02:10 UTC in reply to "RE[4]: ZFS is not "all that""
Robert Escue Member since:
2005-07-08

That's an awful lot of trouble to go through for a web, MySQL or a Snort server. And I really wouldn't derive much benefit from the effort. If the machine was connected to a couple of terabytes of storage things would be different.

Reply Score: 2

RE[6]: ZFS is not "all that"
by sbergman27 on Sun 22nd Apr 2007 03:01 UTC in reply to "RE[5]: ZFS is not "all that""
sbergman27 Member since:
2005-07-24

"""
That's an awful lot of trouble to go through for a web, MySQL or a Snort server. And I really wouldn't derive much benefit from the effort.
"""

What distribution are you using on these machines?

Modern server distributions give you LVM for free during the standard install.

It's one of those things that you may not always need, but if you do end up needing it, you're glad its already in place.

If your server distro does not give you standard server features by default, then I can begin to understand why you think Linux is so limited.

Reply Score: 2

RE[7]: ZFS is not "all that"
by Robert Escue on Sun 22nd Apr 2007 12:23 UTC in reply to "RE[6]: ZFS is not "all that""
Robert Escue Member since:
2005-07-08

RedHat Enterprise Linux 3 and 4. I watched my boss do some of the LVM stuff one day and it reminded me a little too much of managing disks with AIX (which I never liked). The majority of the machines we have are Solaris boxes with about six RHEL machines. All of them are backed up with NetBackup so short of a complete disaster I can recover pretty quickly.

I am using ZFS in production and LVM in what it takes to set it up and use it just doesn't compare.

Reply Score: 2

RE[3]: ZFS is not "all that"
by akro on Sun 22nd Apr 2007 03:56 UTC in reply to "RE[2]: ZFS is not "all that""
akro Member since:
2005-07-06

As a former HP Storage Consultant I am extremely impressed with ZFS capabilities. LVM on Linux and HP-UX can do some of the things, however ZFS really bridge some of the gaps between enterpise storage arrays and low cost jbods. look at some of the potential of the x4500 with the Solaris native iscsi target implimentation and ZFS.

Also managing thousands of luns from an enterprise array is pain, ZFS simplifies that trmendously. Restriping on the fly isn't an option if you need to add spindlesluns wth HP-UX LVM unless you add luns in the same number of the original stripe. ZFS does restriping on write which is a really nice feature when your environment changes.

I worked extensively on the HP Enterprise Virtual Arrays which impliments much of the same concepts of ZFS in the hardwarelun level. Those concepts implimented on the file system are an extremely powerful feature and would be glad to debate them. Needless to say the ability to not tie physical to logical is the way we are going. I just got back from Storage Networking World and virtualize everything is the mantra of the storage world, ZFS is a natural extension.

Reply Score: 4

RE[3]: ZFS is not "all that"
by Arun on Sun 22nd Apr 2007 05:53 UTC in reply to "RE[2]: ZFS is not "all that""
Arun Member since:
2005-07-07

I also don't see what UFS has got to do with it, because volume management is logically removed from the filesystem itself - which is why Andrew Morton complained about ZFS as a layering violation. You could reasonably install a UFS filesystem on a LVM volume and make it work. There's no reason to create a new uber filesystem just to do that and pretend it's something new and cool.

Linux developers calling anything a layering violation is laughable at best. Drivers directly call into kernel functions and all sorts of ugliness exists in the Linux kernel. Solaris is more layered than linux will ever be.

Volume managment need not be logically removed and there is no logical reason it needs to be either. All it does is make managing storage messy and needlessly painful. ZFS' simplicity is testament to exactly why LVM and filesystems should be logically one.

. Goodness, you can even do ATA-over-ethernet. If they'd done that over a network hub I might have found that moderately interesting. A nice and usable GUI representation, overview and interface would have been nice as well. Lame. I also don't get the scrambling of USB sticks into a random order at the end of the video, because...........that's what a RAID array pieces together.

What does ATA over Ethernet have to do with LVM? If your can present a AoE device to ZFS it can user it just like LInux's LVM, The only limitation is using it in a clustered environment.


It's a good example of why Andrew Morton thinks that ZFS is a layering violation, because much of what ZFS does has absolutely nothing to do with file storage itself or a filesystem. Sun pretending that it is just daft.

What is daft is you bringing up Andrew Morton as an authority on storage and file systems. According to his own site he has no experience designing storage systems what so ever. Any one can have an opinion. If you intend on making a big deal of that opinion then the person better be an expert on the subject.

You're seriously telling me you don't think any of that can be done on a Linux system?

If it could there would be no discussion or requests for porting ZFS to linux and this entire article would be moot, no?

Edited 2007-04-22 06:06

Reply Score: 3

RE: ZFS is not "all that"
by comay on Sat 21st Apr 2007 22:23 UTC in reply to "ZFS is not "all that""
comay Member since:
2005-09-16

Actually, Solaris has had an excellent albeit traditional volume manager for *years*. Until Solaris 9, it was an unbundled product but starting in 2002 it was bundled with Solaris.

Your characterization of ZFS has simply a LVM combined with a file system and some glue is sadly mistaken. You might want to visit the ZFS community at OpenSolaris

http://opensolaris.org/os/community/zfs/

to learn why its completely different than a simple combination of those two components.

In particular, look at the Source Tour.

Reply Score: 3

ZFS Fuse
by WereCatf on Fri 20th Apr 2007 21:29 UTC
WereCatf
Member since:
2006-02-15

Hasn't anyone noticed there IS already a working Linux implementation of ZFS Fuse? It's still under work, so it's not optimized, but it's 100% working already.

http://zfs-on-fuse.blogspot.com/

And no, ZFS Fuse is NOT slower than a kernel implementation. The only problem is you can't have a swap on a ZFS pool. But that's not an issue to me.

Reply Score: 5

RE: ZFS Fuse
by phoenix on Fri 20th Apr 2007 21:38 UTC in reply to "ZFS Fuse"
phoenix Member since:
2005-07-11

Can you put the / partition on ZFS using FUSE?

If not, seems pretty useless to me.

Reply Score: 1

RE[2]: ZFS Fuse
by s_groening on Fri 20th Apr 2007 21:49 UTC in reply to "RE: ZFS Fuse"
s_groening Member since:
2005-12-13

You could always create a smaller partition - EXT3 or any other supported file system - to host /boot and leave the rest of / to ZFS Fuse... That ought to do the trick

Reply Score: 4

Nexenta
by DigitalAxis on Fri 20th Apr 2007 22:17 UTC
DigitalAxis
Member since:
2005-08-28

I'd like to know how the legal situation regarding ZFS/CDDL/GPL compares to the apparently permitted situation we have with Nexenta/GPL/CDDL.

That said, I have a feeling the answer has to do with how Nexenta is Debian userland on top of a Solaris system, while ZFS in the Linux kernel would be putting code under different licenses into the same binary file.

Reply Score: 2

v Opensource vs GPL
by spanglywires on Sat 21st Apr 2007 00:12 UTC
RE: Opensource vs GPL
by archiesteel on Sat 21st Apr 2007 04:18 UTC in reply to "Opensource vs GPL"
archiesteel Member since:
2005-07-02

Stick to your half-assed filesystems written by wife murderers.


That is completely uncalled for, and in very bad taste. You just invalidated your entire post. Nice way to shoot down your own argument...

Reply Score: 4

v re :- Opensource vs GPL
by Cass on Sat 21st Apr 2007 02:05 UTC
v Sun hates Linux and Free Software
by anonymousbrowser on Sat 21st Apr 2007 02:17 UTC
ZFS is pretty cool
by deadmeat on Sat 21st Apr 2007 07:20 UTC
deadmeat
Member since:
2006-08-04

From my experiences ZFS is the way disk based storage should have been implemented long ago.

The inclusion of volume management, RAID (software), quotas and the file system in one easy to use package is heaps nicer than LVM and md devices.

Snapshots are just icing. The coolest thing about ZFS is that it's simple and works.

The rest of solaris including the defaults used for installs needs a shedload of work. Just about anybody with some IT skills can install and use a Linux server. Pure Solaris is much bigger challenge.

I haven't tried Nexenta which is a GNU/Solaris type environment. I'm assuming it's much more friendly.

Reply Score: 1

Please understand:
by deb2006 on Sat 21st Apr 2007 18:23 UTC
deb2006
Member since:
2006-06-26

SUN is not interested a bit in Linux. They want to sell hardware and give away a copy of Solaris - not Linux.

Anyway, zfs is much overhyped. If you take a closer look you'll notice that Linux has _roughly_ the same features when you take LVM and xfs/jfs in account.

Reply Score: 2

Moot point if OpenSolaris goes GPL...
by rdean400 on Sat 21st Apr 2007 23:16 UTC
rdean400
Member since:
2006-10-18

Schwartz has posted before about using the GPL for OpenSolaris as well as Java. If OpenSolaris goes GPL, the code will be immediately portable into Linux.

It's better to let technology compete on merit, rather than using intellectual property ownership as a bludgeon for competition.

Reply Score: 1

sbergman27 Member since:
2005-07-24

"""
Schwartz has posted before about using the GPL for OpenSolaris as well as Java. If OpenSolaris goes GPL, the code will be immediately portable into Linux.
"""

Incorrect. Java *might* go GPLv2 first, with the intent of moving to GPLv3.

There has been no talk about GPLv2'ing Solaris, although they have suggested that they might GPLv3 it.

Sun would never allow Solaris' source to be license compatible with Linux.

Remember that GPL is not even compatible with different version levels of itself.

Edited 2007-04-21 23:43

Reply Score: 3

RE: ZFS is not "all that"
by Wes Felter on Sun 22nd Apr 2007 02:35 UTC
Wes Felter
Member since:
2005-11-15

And MANY of the stuff that ZFS does with raid etc is really not needed in any shop that has REAL storage arrays.


One purpose of ZFS is to eliminate the need for "real storage arrays".

Reply Score: 2

Patents should not be a concern
by Wes Felter on Sun 22nd Apr 2007 02:41 UTC
Wes Felter
Member since:
2005-11-15

Realistically, Sun cannot sue open source developers after it has put out so much PR about helping the open source world; patent lawsuits would instantly brand Sun as "evil" in the press.

Reply Score: 3

difference between zfs and lvm
by kometen on Sun 22nd Apr 2007 09:12 UTC
kometen
Member since:
2007-04-22

Read the comments that zfs is nothing more than lvm plus some journaling file-system. I haven't worked with Linux nor lvm but have worked extensively with FreeBSD's UFS2 and Verita's vxfs and volume manager. FreeBSD's UFS2 does not scale when used as storage whereas vxfs is heavily used when reliability and scalability is a requirement.

I have deployed some servers for internal use with zfs and boy is this easy, taken from the zfs examples:

zpool create tank raidz2 da0 da1 da2 da3 da4 da5 da6

zfs create tank/home
zfs create tank/home/linus
zfs create tank/home/morton

zfs set mountpoint=/home/linus tank/home/linus
zfs set mountpoint=/home/morton tank/home/morton

How would a similar process using lvm + journaling filesystem be done in Linux?

regards
Claus

Reply Score: 4

DeCSS?
by FunkyELF on Mon 23rd Apr 2007 14:26 UTC
FunkyELF
Member since:
2006-07-26

Could this be like DeCSS where it is legal in one or two countries but people in all other countries use it anyway?

Reply Score: 1