Slashdot Mirror

← Back to Stories (view on slashdot.org)

JFS May Make It Into 2.4

Posted by ryuzaki0 on from the is-like-the-diary-of-robinson-crusoe? dept.

Grimsaado writes: "LinuxWorld has an article on IBM's JFS and how it might be included in 2.4 as well as some technical fluff on it's phenominal cosmic power." Heck, with the number of journaling file systems, it's like being at a file system buffet at this point.

23 of 191 comments (clear)

  1. Reiserfs, journalling only part of the picture by Anonymous Coward · · Score: 5
    The ReiserFS really rocks, but journalling is only secondary. The ReiserFS is much more than a journalling filesystem. It is supposed to ultimately be some sort of object oriented user-configurable file system with personality plug-ins and all sorts of bells and whistles. Me, I'm only interested in the journalling aspects at present. It is rock solid now and I won't go back to ext2 anytime soon. The only thing I miss with ReiserFS is extended attributes like immutable and append-only. These are planned for a future release of ReiserFS, however.

    If Linus has a problem with ReiserFS, it is that he probably fears some of the exciting new ``disruptive'' concepts that Hans Reiser has planned. ReiserFS is truly innovative. For those interested in the innovations, there is a White Paper available. I'm sure that Hans Reiser's roadmap is what is scaring Linus. I'll be happy to see JFS make it into 2.4, but ResierFS deserves to be there too. I urge anyone with a slight interest to try out ReiserFS. I'm sure you'll agree then that it deserves a place at the table. I'm a late adaptor, and skeptical of new code (I used Xia FS for years after ext2 was available). If conservative old me can handle ReiserFS, anyone can.

    1. Re:Reiserfs, journalling only part of the picture by Noodles · · Score: 4

      Thanks, Hans.

    2. Re:Reiserfs, journalling only part of the picture by kzinti · · Score: 4

      Thanks, Hans.

      <Grin>.

      But seriously: that AC was right. ReiserFS is more than just a journaling filesystem, and it's rock solid. I started using it on my laptop as a patch applied to my 2.2 kernel. I had also been using Suse's USB backport patch, but it was crashing my laptop (some kind of interaction with APM), and I got tired of waiting for 8GB of ext2fs partitions to fsck.

      Under normal operation, the ReiserFS is fast and reliable. In fact, most of the time I forget that there's anything special about the filesystem. In recovering from a crash, though, the reisers really shine -- they recover nearly instantly. Only once have I ever lost data: my battery ran down, and a file I had been editing was empty after I restarted the laptop. But even this may not have been the fault of the filesystem; the laptop may have powered down at just the wrong time during the file-save cycle, just after ftruncate, but before any data had been written.

      Anyway, journaling filesystems are not magic -- they can lose data. Read that again: they can lose data, just like any filesystem. They just recover much faster because they guarantee the integrity of the metadata.

      Bottom line: ReiserFS gets two thumbs up. Highly recommended if you're not afraid of patching your kernel.

      --Jim

  2. Re:Not JFS, but it plays one in a marketing brochu by norton_I · · Score: 3

    Well, IBM's "JFS for Linux" is based on their port of JFS for OS/2 (remember that?) as opposed to their JFS for AIX, which is what most people associate with the name.

    The current JFS for Linux project is, for instance, still case insensitive. Hardly an acceptable situation for a UNIX filesystem, but hopefully one that can be fixed.

  3. IBM JFS site by onion2k · · Score: 3

    Theres more about this thing at http://www-4.ibm.com/so ftw are/developer/library/jfs.html. One irritating thing about it is that theres no support for floppy disks, or other small removable media. Understandable considering the system, but floppy disks are still quite handy. (Assuming the page I was reading is up-to-date)

    --
    http://twitter.com/onion2k
  4. Doh! by Greyfox · · Score: 4
    Disclaimer: Since the article is slashdotted, I haven't had a chance to read it yet. That being said...

    Sure, let's just piss in Hans Reiser's petunias. A lot of people I've talked to seem to thing that Reiserfs is the farthest along journaling filesystem and I'm sure including some other journaling filesystem in 2.4 would be a major poke in the eye for him.

    --

    I'm trying to teach myself to set people on fire with my mind... Is it hot in here?

  5. No it won't. by shippo · · Score: 4
    Adding any journalled filesystem to the existing kernel requires significant changes at the VFS layer. Making such a change has the potential of breaking other things, particularly other file-systems. Every current filesystem will have to be rechecked - not a simple task as some don't have full-time maintainers.

    The current 2.4.0-test kernel is getting very close, and Linus now appears to be only accepting bug-fixes and the odd self-contained driver. There is no way such fundamental changes could go in now.

    1. Re:No it won't. by Azog · · Score: 3

      I agree - it won't be going in. I read the Linux Kernel mailing list, and I haven't seen a single post on JFS in the last week.

      It seems the biggest problem at the moment is last minute changes in the VM - Ric Van Riel has rewritten parts of the VM to be much faster, but there are some deadlock problems and other bugs being worked out.

      On the other hand, many people are testing prerelease versions of 2.4.0 with the ReiserFS patches and not having problems. Even if ReiserFS doesn't make it into the official kernel release it will probably continue to be a "standard" patch and available in many distributions, such as SuSE and Mandrake.

      There are already big improvements slated for the 2.5 series - a cleanup of all the IDE code, for example.

      Torrey Hoffman (Azog)

      --
      Torrey Hoffman (Azog)
      "HTML needs a rant tag" - Alan Cox
  6. Buffet - all you can't eat. by 11223 · · Score: 3
    Heck, with the number of journaling file systems, it's like being at a file system buffet at this point.

    None of which can read/write BFS at this point, despite the fact that it's well documented in Practical File System Design with the Be File System by Dominic Giampaolo.

    Grumble grumble complain complain...

  7. Re:But ... security .. ? by ssimpson · · Score: 3

    Scramdisk is currently being ported from Windows 95/98/ME & NT/W2k to Linux (by myself and AJ). This will allow the creation of a "virtual container" that can contain any filesystem - including filesystems that implement journaling.

    --
    "Mary had a crypto key, she kept it in escrow, and everything that Mary said, the Feds were sure to know."
  8. Re:OS/2 version? by SEE · · Score: 3

    Actually, he heard right ;-).

    You see, while JFS is available for OS/2 Warp Server for e-Buisness (Aurora, Warp 5 Server), it's not available for the workstation version of OS/2, OS/2 Warp 4.5 (Merlin with the kernel update fixpack).

    So a project was put together to take the GPLed JFS code and get it to run on OS/2 4.5.

    Steven E. Ehrbar

  9. Re:Kernel Archives by shaggykl · · Score: 5
    I'm from IBM.

    As previously stated JFS is released under GPL.

    AIX's JFS contains licensed code from outside sources. Several years ago, JFS was redesigned from the ground up for OS/2 Warp Server. This version does not contain any encumbered code and was designed to be more scalable than AIX's version. This JFS first shipped last year with Warp Server for e-Business.

    Therefore, the Linux offering of JFS is not the same filesystem you'll find on AIX, and you won't be able to share a JFS file system between AIX and Linux. (You will be able to share one between Linux and Warp Server.)

  10. Can any of these journalling FSs undelete?? by Bazman · · Score: 3

    Thats my biggest fs problem at the moment. The average home user can go make a cup of coffee while the machine fscks after a crash. Even our departmental server doesnt take that long. But just about the only time I've ever had to restore stuff from backups is when people have done

    rm * .tex

    or similar. I do all this backup nonsense just to protect themselves against their own stupidity?

    So, are any of the journalling FSs smart enough to rollback a journalled transaction to undelete a file? And provide user-level tools to do it?

    I know there is the beginnings of undelete support in ext2 FSs, but its all very beta. Surely when designing a new FS you'd factor it in from the start...

    Baz

  11. Buffet.. by TheTomcat · · Score: 4

    Heck, with the number of journaling file systems, it's like being at a file system buffet at this point.

    Mmmmm.. all you can eat inodes.

  12. Read the kernel list... by dpilot · · Score: 3

    Bingo!

    This came up months ago on the kernel list - simply the weekly summary, even.

    Journalling requires changes in the VFS. Rather patch the VFS many times for each member of the 'buffet' of journalling filesystems becoming available, Linus said he'd prefer to find the common elements, and make VFS "journalling-ready".
    The individual journalling filesystems would have to work with the new VFS to make sure it was suitably changed, and to make sure their code would work with it.

    This sounds like the correct approach to me, even if it does delay things a bet. Better than letting ad-hoc adaptations creep into the kernel.

    --
    The living have better things to do than to continue hating the dead.
  13. ReiserFS in RedHat by NetJunkie · · Score: 4

    Someone has changed RedHat 7.0 to allow you to install ReiserFS during boot.

    http://cambuca.ldhs.cetuc.puc-rio.br

  14. well, there's one FS I won't configure by jetson123 · · Score: 5
    I was using JFS under AIX for several years. I can't imagine why people would want to run it. It doesn't give you much more data security (only file system structure is journalled), and you pay a heavy price in terms of performance. In fact, running Linux and AIX side-by-side for several years, Linux with ext2 on a low-end IDE drive not only greatly out-performed AIX on a high-end workstation and SCSI drive, AIX even lost a file system during a crash.

    Fsck on ext2 is pretty fast, crashes are very rare for server systems, and servers require regular backups anyway. It is more rational to run integrity checks in batch mode when necessary than to pay overhead on every file system access to deal with the possibility that the machine might crash at any moment. I think JFS (and its companion, LVM) are simply not good engineering tradeoffs for most (all?) applications.

  15. not forking but... by josepha48 · · Score: 3
    .. including everything.

    It seems these days that everything is getting into the Linux kernel. While this is great, I imagine there are going to be some newbiew that are thinking which should I choose, which is better. The answer is more of what are your needs.

    I wonder how distros are going to handle this. If a distro includes only support for one, then a user will have to choose the distro based on the fs he wants, if they include all the user then has to choose which one he wants to use.

    Since this is compiled into the kernel can you use more than one journaling file sytem at a time?
    Can I have one partition using ext3fs, one using reiser, and one using IBM's jfs, and one using XFS? Not that I'd want to though.

    I don't want a lot, I just want it all!
    Flame away, I have a hose!

    --

    Only 'flamers' flame!

  16. Does anyone know the meaning of the word DESIGN? by Otis_INF · · Score: 3
    I mean: if people stop coding instantly and start designing the stuff for a change, the VFS can get universal for _ALL_ kind of filesystems: plug 'em in and they'll run. Why o why do people start coding their own freaking filesystem without a proper motherlayer first? I know there are rivaling opinions about what the VFS should do and what it shouldn't do but, please... this kind of software development seems to me erm... rather unsuccesful.

    "Hey, the last 9 months I programmed on this superduper filesystem and it will be great for the next Linux Kernel!"

    "Erm.. yeah, great but the VFS layer isn't up to par so we can't use your functionality in the rest of the system anyway"

    Besides that... Linus isn't stupid. He already mentioned a zillion times he wants to end the featurecreep and finish the kernel. Now adding another filesystem will definitely delay the kernel's release BECAUSE of featurecreep, something Linus wants to avoid.

    But.. with a better design of the system internals, this wouldn't have to be necessary: IBM would just add another module and everything would have been fine. ah well...

    Good old.. mr. Tanenbaum ;)
    --

    --
    Never underestimate the relief of true separation of Religion and State.
  17. Kernel Archives by Dios · · Score: 3
    Hmm.

    as far as I have read on kernel threads (http://kt.linuxcare.com) there will be no journalling systems in 2.4, initially at least.

    This is kind of an odd announcement especially with the kernel in its current 'slushy' state.. I am guessing that 2.4.X with X>5 before the first journalling systems begin to appear.

  18. Re:Not JFS, but it plays one in a marketing brochu by rhaig · · Score: 3
    • The current JFS for Linux project is, for instance, still case insensitive. Hardly an acceptable situation for a UNIX filesystem, but hopefully one that can be fixed.
    actually, if you'd go look, you'd see that as of release 13 of JFS (September 29, 2000) is now case sensitive. But I suppose you can't be bothered to research something before you flame about it.

    Having been a contractor at IBM in Austin, and having spolen personally with some of the AIX developers and their managers, I can state that IBM groks open source. (at least the departments I've had contact with did) IBM's JFS may not be the most mature journalling filesystem for linux out there, they aren't claiming to be, but it is another one. When it's all done, we'll probably have a couple of jfs's left (one that only journals meta-data, and one that journals both data and meta-data) and they'll likely have incorporated the best pieces of the jfs's that have fallen aside. Isn't that what it's all about? So all you people who spread doom and gloom about IBM and open source, just stop it. We're sick of it ok?? What about Sun?? They've pissed on the open source community and yet what of them? Oh, that's right... they're not IBM. Evil big blue brother IBM. get off your high horses and accept that they're doing something good for you.
    --
    "We are not tolerant people. We prefer drastically effective solutions"
  19. But ... security .. ? by Troed · · Score: 3
    Can this be combined with a secure filesystem? We're talking so much about securing our machines, but very few users run them with a secure filesystem. Myself I only use e4m with mapped drives on my Windows machine, which isn't good enough (doesn't encrypt web caches etc). Any new file system, whether it's journaling or not, should have built in security if it can't be done on top of it.

    (When I log out of my machine, I want to _know_ that the contents on it can be reached by myself only - no matter what any repairman, hacker or ... police, does)

    --
    it's in my head
  20. Standard OpenSource Advocate response... by Anonymous Coward · · Score: 4
    If you think that the 2.4 kernel is 'long overdue' then why don't you volunteer and help out the effort? That's the benefit of Open Source Software, whenever someone makes a negative statement about the software, then one gets to tell them to 'work on it themselves'. it doesn't matter if you are busy, employed, don't know C or C++, or that the person telling you this has never even seen the kernel source code. They get to tell you to fix your problem yourself.

    Isn't Open Source wonderful?