Journaling file systems used to be an oddity primarily for research purposes, but today it’s the default in Linux. Discover the ideas behind journaling file systems, and learn how they provide better integrity in the face of a power failure or system crash. Learn about the various journaling file systems in use today, and peek into the next generation of journaling file systems.
I find that a pretty daft thing to write. ReiserFS is still used by a great many people because it still does what it was designed to do very well, and there were more people involved with ReiserFS than Hans.
Its usage has diminished mainly because the focus of development was switched from maintenance of Reiser 3 to a new and completely incompatible filesystem in Reiser4 that people weren’t just going to reformat and move to overnight. While I still expect lots of useful things to come out of Reiser4, it serves as a bit of a warning to people who think they can just breeze in with a totally new and uber cool filesystem and expect it to be widely adopted.
Additionally, I don’t see widespread adoption or support of JFS at all. You usually have to jump through some pretty reasonable hoops to get JFS on most distributions, and XFS holds more confidence for more people in most use cases for such a filesystem.
Edited 2008-06-12 21:52 UTC
I quite agree, it’s not like he loses his copyright because he is imprisoned…
Yeah, but if you’re the kind of person who refuses to use software from anybody you consider “evil”, you’re gonna need to add ReiserFS to your list. I mean, if you’re gonna lump Microsoft into that category, you have to do the same for Reiser … right? ;-p
Blah, blah, blah, blah, blah, blah blah. Everybody hates Microsoft, there’s some conspiracy to hate Microsoft, everybody does everything because they hate Microsoft etc. etc. This complex does the rounds on a lot of MSDN blogs I’ve seen, and it’s just plain sad. Whatever the whys and wherefores of Hans Reiser, the code lives on regardless. Microsoft has a track record of being derogatory about open source software at every turn, so no, many people aren’t just going to start liking Microsoft until they throw them a serious bone.
Either deal with that, or get yourself a wigwam outside of Redmond and go and live there.
Edited 2008-06-13 14:31 UTC
This is getting REALLY off topic, but it was such a stunning post I couldn’t help but comment
Let me get this straight. Your definition of “Evil” is being “derogatory about open source software”? That really blows my mind…
http://www.mono-project.com/Moonlight
They paid for top quality HD codecs (WAY beyond theora, which is the best out there in the oss world), said they wouldn’t sue over use of technology they own, and helped out with development.
http://www.microsoft.com/interop/
The big move inside the company to play well with its competitors, which we have already started seeing the results of
http://port25.technet.com/
An effort to help integrate linux into MS based environments
http://www.microsoft.com/opensource/community.mspx
A list of open source businesses that Microsoft has partnered with (MSCP means you get pretty much all microsoft software for free or next to nothing)
http://www.codeplex.com/
Microsofts hosted source code/community site for open source projects
http://www.microsoft.com/interop/osp/default.mspx
Microsofts promise not to sue over use of a whole bunch of protocols and formats they own patents on
The big move inside the company to play well with its competitors, which we have already started seeing the results of…
Play well with competitors, huh? Either Microsoft buys them, or smashes them with dirty tricks. Who do you think financed the SCO lawsuits? Who do you think lobbied the US congress to make America’s odious software patent laws even more odious? Or who has been pouring millions into lobbyists pockets to get the European Commission to saddle Europe with software patents (so far, unsuccessfully). And who forces computer manufacturers to buy a Windows license for every computer they sell, even if the customer doesn’t want Windows pre-installed? Who paid shills to post all sorts of messages to BBSs saying how lousy OS/2 was (and continues doing this to Linux)? And (though Microsoft denies it) there was that whole “NSA Key” thing, plus all the DRM stuff in Vista.
Microsoft has done its part to screw up the US’s legal system, and keeps trying to screw up the legal systems of other countries. And smash competition any way they can. And violate your privacy. Bill Gates should be put in prison for some of the things he’s done.
A whole bunch of people did. Microsoft paid sco money to liscence UNIX to make their UNIX tools
Link? Microsoft is constantly calling for patent reform, they are the biggest targets and get sued more then anyone over software patents.
Again, where are you getting this information?
Nobody. If you bring up what they did to be, I’m just going to say the same thing about pre and post anti-trust suit microsoft
Microsoft from 30 years ago is a very different from microsoft now. That is my whole point.
Dude, you are off your rocker
a) What does either have to do with being “derrogatory towards open source
b) What does allowing for playing HD-DVDs have to do with anything?
How?
Look at the ten or so links I just posted, most of those have to do with working with competition. Again, MS now is not the same as MS 20-30 years ago.
[/q]Bill Gates should be put in prison for some of the things he’s done. [/q]
(http://en.wikipedia.org/wiki/Bill_and_Melinda_Gates_Foundation)
Indeed, a shifty character if I ever saw one…
Edited 2008-06-13 16:18 UTC
Would you guys mind to discuss journaling file systems? I could care less about your MS hate/fanboism.
Thanks in advance.
Uh, huh.
I think we’ll stop right there ;-). See my original comment about people with complexes banging away on their MSDN blogs :-).
Since we’re talking about ReiserFS, which is open source, and this idiot is telling us that since he thinks that everybody thinks that Microsoft is evil we should stop using ReiserFS as well…… Does that blow your mind enough?
Ahhhhhhhh, Moonlight. If Silverlight ever gets to a critical mess, we’ll come back and see how compatible Moonlight is then, OK? This is a technology where Microsoft is behind. I did mention track record, right?
Where is the source code, what is the license and who controls said codecs? A promise not to sue, is just that. A promise, and a promise is not legally binding. Additionally, Moonlight has no codecs to speak of, and can only use ffmpeg currently.
No evidence of that happening. Contributions to Samba? Contributions to Open Office? You know, actual code?
I think you might want to take a look around and see if there is actually anything useful on there ;-).
Vice versa? Errrrr, no.
Show me the code ;-). I have yet to see anything of note come out of that for anyone apart from soundbites about how Microsoft is now so open source friendly.
Yes. Open source projects on their platforms with not a single line of code from their platforms in sight.
That makes me feel so much better. The OSP is a promise and not a license, and legally speaking means zilch. It also only applies to you if you take a piece of technology as-is, so if you embed it into another project that does something different, hmmmmm. That’s not covered.
It’s all smoke and mirrors, or as former Microsoft employee Joel Spolsky says, fire and motion ;-).
Hmmm. Congratulations. You’ve just violated the terms of service for OSNews.
Choke on your double-standard.
Moonlight IS part of that track record, but apparently, NOTHING that MS could do would overcome your double-standard.
Since when is contributing codec source code necessary to avoid being called “evil”? There are lots of ways to contribute to open source without contributing source code. FSF lawyer Eben Moglen doesn’t contribute source code, but his legal contributions make it possible for open source to thrive. Microsoft contributes codecs to Linux. It makes Linux a more vibrant platform for users. But your narrow view of the universe is too twisted to recognize “contribution” as anything other than source code. Well, you’re wrong.
Provide a link describing somebody that Microsoft has sued for patent infringement. I’d really like to read about it.
So what. When was the last time that the Samba developers contributed to Open Office? Or vice-versa? Why is it necessary for devs to contribute to your pet projects in order to avoid being called “evil”? Are all developers who don’t contribute to Samba and Open Office “evil”? If not, why? You’re twisting yourself into knots.
How about the source code for the .NET Framework?
Windows Services for Unix.
Apparently, you’re not looking at all.
Show me ANYBODY that Microsoft has sued for patent infringement.
Red herring. OSP code is licensed to you with fairly generous terms, but it doesn’t let you re-license the same source code separately; nor do you really NEED to do that at all. You’re just throwing any crap you can think of against the wall, and hoping that some of it will stick.
Look at who’s at the bottom of the thread, and where this starts, mate ;-).
What double standard? The two aren’t comparable, which is the point I believe.
Yes, it is.
You mentioned a track record of open source credentials. That means code. I don’t know why you keep mentioning the word evil here. You’re the one who made that accusation, and you’re the one with the complex about everybody thinking that Microsoft is evil.
Alas, that isn’t a get-out for you. Read the OSP and tell me if it is a legally binding license.
Why would they want to do that? The two projects are different. I’m saying that if Microsoft wanst to be taken seriously as an open source company committed to interoperability, there’s a pretty damn easy way to prove it.
Why are you mentioning the word evil again? You sound like one of those saddos on banging on his MSDN blog trying to tell us that everyone hates Microsoft and everything is an IBM conspiracy.
Errrr, no. If they want to be taken seriously about interoperability and open source contributions, there’s a damn easy way to do it.
Errrrrr, no. I think you’ll find that any code there is Rotor. You won’t find the code for the .Net framework.
Windows Services for Unix and Linux, running on Linux and Unix? Errr, no.
It ain’t there.
That’s not a get out and doesn’t paint over how pointless the OSP is I’m afraid.
The OSP is not a license, as I’ve pointed out.
Errrrr, cross pollination of source code from one project to another is an absolute cornerstone of any open source project and the open source world. Without it, there is no point.
You’ve addressed absolutely nothing sweetheart. It’s all fire and motion.
A promise is comfort to a fool right?
That doesn’t really seem to be the point they were trying to make with that sentence though, all they were saying was that its continued development/enhancement are in a state of flux, since Hans is in fact the principal author/designer, and the fate of Namesys if he does wind up in prison remains to be seen.
Edited 2008-06-13 03:59 UTC
It isn’t daft, Namesys has pretty much fallen to pieces, and no real work is being done on reiserFS anymore.
Interesting article (allthough it does not go very deep into technology, but introduces a starting point), especially the section “Variations on journaling”. It explains how data and metadata is handled for different modes to avoid inconsistencies. Remarkable: The more security, the less performance, as it seems. It has been mentioned that is it not always clear when writes from journal take place, and how metadata is handled in relation to the corresponding data blocks.
This is a difference to performant file systems like the Fast File System (FFS, also known as UFS) used by the BSDs. There, the metadata is written asynchronously in a definite order, so the file system’s “on disk status” is always consistent, which may not the case in the mentioned journaling file systems under certain circumstances.
The article mentions that journaling file systems have the advantage that it’s not neccessary to wait for the fsck utility at startup when a file system problem is recognized, for example after an unclean system shutdown. BSD’s fsck utility is able to run in the background while the system is booting up and running, so there’s no need to wait for it to complete. This is not a “journaling FS feature” only.
And I still know XFS from my good old SGI beauties… =^_^=
Does anyone know if Linux / XFS can read Irix disks, or if Linux / JFS can read AIX disks?
Even if the filesystems are on-disk compatible, I imagine there are endianness and incompatible logical volume management issues.
In the days of yore I thought that JFS2 was only in AIX 5 and JFS1 was in AIX 4, Linux, and OS/2, but the Wikipedia article says otherwise.
This may answer your question:
http://oss.sgi.com/projects/xfs/faq.html#useirixxfs
Thanks, that implies that XFS is endian-neutral, which is interesting.
They’re just incredibly robust and reliable.
It’s great to boot my Linux box in the evening and be
*absolutely certain* that it will boot just fine. Sheesh, the number of times that Win XP blue-screened on me in the far-distant past when I used it…
Ok, it’s true that OS robustness is due to more than just the file-system, but a good journalling FS sure helps…
FreeBSD is interesting too, with its “soft-updates” in its file-system. That’s ultra-robust as well.
Ive heard that most systems work fine during light load and easy tasks. Even WinXP works fine then. The problem is when you scale up things. Will it still work, under demanding circumstances? Will WinXP work with 99.999% uptime? Will Linux filesystems work with Petabytes of storage, and will it work fast and reliable? And how about fsck petabyte filesystems? Will it take the entire weekend (yes it will)? Etc.
It seems that only ZFS is able to cope with all these issues.
For instance, a new 1TB drive has 20% of its space allocated for error correction. There are so much errors in large drives that it isnt funny. ZFS makes the assumption that the drives, IO cards, etc WILL fail. And ZFS copes with these errors. It is the only one detecting silent corruption (and correcting them). All this issues new drives faces and more, are discussed here:
http://www.acmqueue.org/modules.php?name=Content&pa=showpage&pid=50…
There are always trade offs for filesystems. Some work best with large amounts of small files, others work best with constant reads to big files. Some are geared towards the desktop (including stuff like rich metadata, or moving system files to the middle of the platters for quick access), others are geared towards servers (like ZFS, which you just mentioned)
I still think of journalling as an oddity.
While journalling writes the (meta-)data
twice to the disc, softupdates just change
the order of writes, therefore also elimi-
nating the need to run fsck (except to re-
free storage marked as allocated).
That said, our (the BSDs’) fsck still sucks.
Another thing is Log-Structured Filesystems
like 4.4BSD LFS. It has a very interesting
concept, but the current implementation lets
people not believe in it and is buggy (while
it worked in NetBSD®, only up to 60% of disc
space can be used cleanly).
Reiserfs looks, to me, more similar to LFS
than to a journalled filesystem. I agree to
keep an eye on it, as it’s interesting too.