IBM releases JFS to GPL

PinAngel writes "IBM has released its JFS source code for Linux to the GPL. You can read more at the IBM website. " JFS is their Journaling File System - you can grab the latest tarball from their Web site.

Comments

Journalist file system

[JustShootMe]

So... what? Does this mean that the JFS will now misreport your disk usage, burrow through your hard drive for nasties and send them to the editor for publication?

What's that? It's not the Journalist File System? Never mind then.

If you can't figure out how to mail me, don't.

Choices?

[ilkahn]

After reading these first few comments, I decided that the tone of quite a few of these posters scared me! "Why do we need more journaling file systems?" they said? Don't we already have ReiserFS, ext3, and of course xfs? Don't we already have some? Why can't IBM just put developers to work on a journaling file system we already have?

Well, quite frankly, I LIKE having a choice? Why doesn't everyone that works for RedHat work on making the Debian project better? Hell, why do we have so many editors, vi, vim, emacs, joe, nedit, gnotepad, ed, pico... why do all of those people have to make their own editor? Why can't they just contribute to an editor that already is there?

Er... maybe because it fits a slightly different niche and philosophy? Maybe because IBM's journaling file system handles things a little bit different then ReiserFS, and for certain applications one or the other might be better? I like choices! I like competition! This much diversity is a sign of a healthy enviroment... I say, let them write their own journaling file systems, let's get 10 or 20 more, each a little bit different, each a slight bit more focused to a certain area. Diversity is wonderful, let's nurture it.

Journalling File Systems for Linux

[jd]

Here's a brief summary of what's out there, and how I think JFS is fitting into this picture:

• ReiserFS-journalling : Supports metadata journalling only. Reiserfs' performance is superior to most other filing systems out there.
• Ext3fs : Supports metadata journalling only? Ext3fs is Ext2fs + journalling, so is essentially compatiable.
• XFS : Only partially released. Impossible to say what XFS for Linux will actually do, or how well it'll work.
• JFS : Mostly working, from the sounds of it. The TODO lists logging as incomplete. Nothing on the web pages as to what type of logging is done, but I'm going to guess it's full journalling.

JFS is the =ONLY= working journalling filing system from a commercial company. XFS would have been the first, but there needs to be more released (and soon) if anyone is to have much confidence in it.

Working does =NOT= mean functional or usable, though, but the development is in TRUE Open Source style, with bug-reporting and a read/write CVS repository for developers.

As for when distributions will use this - I don't expect to see any distribution use ANY of the journalling filing systems this quarter. Next quarter, we MIGHT see ReiserFS. This year, I'd expect to see ReiserFS and Ext3fs.

I'd expect to see JFS added to the next development tree, and therefore introduced into distributions in the next cycle of releases.

XFS might (or might not) come out before the year 3000. As far as kernel patches go, SGI are brilliant. As far as graphics, especially OpenGL, go, SGI is untouchable. As far as filing systems go, a concussed doormouse in a tarpit would move faster.

True Blue Big Blue

[nullspace]

It is very encouraging to see IBM donate their products to the community. It is also very encouraging to see that they release it under the GPL. It is very important to keep new products under the GPL since it is the more accepted license and allows for the greatest benefit to the user and those who wish to enhance the product.

I work in close affiliation with IBM and every indication that I am receiving is that they are totally genuine about their open-source actions. IBM seems to be falling into a model that allows for the greatest customer satisfaction: supporting many diversified products, listening closely to customer demands, and opening up their products to the community. I would like to see more companies follow their example. In the end users will benefit the most!

The new currency in an Open Source World

[Soko]

A hearty "thank you, way to go" and other compliments to our friends at IBM. BTW, I've heard muted rumblings that DE.. ooops, Compaq is thinking about porting AFS (which, by the way, is killer) to Linux as well. I started thinking "great, more competition, more confusion, it's going to be a while before I know which one to support, at least until one has bumped off most of the..", then it hit me. Competition, in it's best form.

A journalling file system is a really critical need for our favorite Open Source OS to be taken seriously in an enterprise setting. IBM, SGI et. al. want to be able to say "See, we initially wrote your FS, so we can suppport it best!", and get more business that way. I think that's why there are so many competing projects.

This, friends, is where a new market paradigm begins - we will decide which new FS becomes the standard on our machines, based on it's merits, not marketing. Then we end up supporting it, and by default, the company that created it. It's the new currency - knowledge, the ability to use that knowledge, and our collective mind set because of that knowledge. Welcome to the new world.

Re:Pretty Cool; Hopefully some useful ideas

[Mr Shark]

I just downloaded the code and have had a quick look at it. It seems to contain

• a dump of the AIX/OS2 code (or something close to it) as a reference implementation (also GPL)
• a first grab at a "kernel patch" (its a tar ball that unpacks over the 2.2.12 tree).
• directory containing source code for some utilities and something that looks like the implementation under os2 (#include :-) as a reference
• Not much documentation except for the reference implementation, but then again code is the ultimate technical documentation:-)

I would say that the only thing missing is something like the README on the web page in Documentation/fs/jfs.txt (hint, hint)

Joy, JFS is a good fs, during the two years now that I have been working with AIX I have had one fs corruption, and that was fixed when we fastened the SCSI-1 cable

Not complete yet!

[retep]

Note that JFS isn't complete yet. The README says that hard and soft links do not work, you can't *write* to a JFS filesystem, reading is still in progress and it will only work on the Intel architecture due to endian problems. If you want to use a journeling file system now you should probably try ext3

Too many choices are bad

[Per Abrahamsen]

Your argument is heard often, which is really scary, because it is based on the false premise of infinite developer ressources.

Think about the situation before Qt/KDE and Gtk/Gnome, where we had a dozen different GUI toolkits, all of which sucked badly, and none of which had a momentum significantly larger than the other. An application writer would have to choose one of them, and send fixes and enhancement to one that alone, helping perhaps 5% of the other application writers in the process. Today, he can one of the two main toolkits/environments, and his fixes and enhancements will help maybe 45% of the other application writers.

Of course, some choices can be justified because they provide compatibility, for example LessTif, GnuSTEP and winelib, and there should always be room for research-like projects. What is needed is one or two choices that are clearly "mainstream", and thus can be used for focusing developer energy.

For journaling file systems, the situation isn't all bad. XFS, JFS and Ext3 are all clearly needed in order to support interoperability with SGI, IBM and Ext2 systems. And ReiserFS has some very interesting application for file system based databases, which I'm really hoping will turn out good.

Linus only has 24 hours in the day...

[Christopher B. Brown]

At some point, whatever journalling "options" get officially supported will require some attention by the "senior kernel folk," whether that be Linus, Alan Cox, or (fairly likely!) Stephen Tweedy.

These filesystems are not as simple to interface in as the "Amiga filesystem" or other such stuff, as these FSes have expectations to be able to control somewhat how the kernel manages caches. They're not merely "drop in a patch and all will be well."

As a result, while I agree that it's good to have some diversity now to allow some experimentation, I am far less sure that it will be wise to have four (or more, if rumors of Compaq contribution of AdvFS code turn out to be true...) filesystems integrated in to the "official" kernel stream. There may be merit to having a couple of them, but not likely all of them.

So while I agree that it's quite OK for there to be 5 of them (and that ignores GFS, NTFS, and other stranger options that may be of less direct relevance), I think that there will be, ultimately, a need for several of the "integration projects" to fail.

Otherwise, Linus and others won't have time to fix up NFS3, improve memory management, implement ACLs, implement capabilities, implement IA-64 support, and all the other sorts of things that need to occupy some of their time.

The GUI comparison was pretty good; I agree with Per that it is a Good Thing that we have GNOME and KDE, as this is sufficient diversity to ensure that there is some competition whilst not being so much as to be completely fragmenting. It is unfortunate that this leaves some potentially good toolkits like FLTK or Tk or Amulet or Garnet or InterViews "out in the cold."

The point is that variety is useful at the point in time at which you're not sure what the results should look like.

But after that point, variety comes at the cost of having to support additional "development streams," and while there is logic to "letting the best man win," this has the side effect that if you agree with this, you have to also agree with the notion that the "not quite best men" need to be able to lose.