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GNU/Hurd Delayed To Fix Disk Size, Serial I/O Limitations
gregger writes "This Infoworld article indicates that the GNU/Hurd is still waiting to stampede. Evidently they have to switch from the GNU Mach implementation they're using now to OSKit's Mach which will help them support faster serial I/O and larger hard discs. Currently GNU/Hurd will only support somewhere between 1 to 2 GB partitions."
http://www.gnu.org/software/hurd/hurd.html
GNU HURD is a slimmer re-write of the UNIX kernel that is completely OOP.
Here's a cut and paste from the homepage:
The Hurd is not the most advanced kernel known to the planet (yet), but it does have a number of enticing features:
it's free software
Anybody can use, modify, and redistribute it under the terms of the GNU General Public License (GPL).
it's compatible
The Hurd provides a familiar programming and user environment. For all intents and purposes, the Hurd is a modern Unix-like kernel. The Hurd uses the GNU C Library, whose development closely tracks standards such as ANSI/ISO, BSD, POSIX, Single Unix, SVID, and X/Open.
it's built to survive
Unlike other popular kernel software, the Hurd has an object-oriented structure that allows it to evolve without compromising its design. This structure will help the Hurd undergo major redesign and modifications without having to be entirely rewritten.
it's scalable
The Hurd implementation is aggressively multithreaded so that it runs efficiently on both single processors and symmetric multiprocessors. The Hurd interfaces are designed to allow transparent network clusters (collectives), although this feature has not yet been implemented.
it's extensible
The Hurd is an attractive platform for learning how to become a kernel hacker or for implementing new ideas in kernel technology. Every part of the system is designed to be modified and extended.
it's stable
It is possible to develop and test new Hurd kernel components without rebooting the machine (not even accidentally). Running your own kernel components doesn't interfere with other users, and so no special system privileges are required. The mechanism for kernel extensions is secure by design: it is impossible to impose your changes upon other users unless they authorize them or you are the system administrator.
it exists
The Hurd is real software that works Right Now. It is not a research project or a proposal. You don't have to wait at all before you can start using and developing it.
You say things that offend me and I can deal with it. Can you?
IIRC the partition size limit is due to the fact that the filesystem server mmaps the partition; on 32-bit systems there isn't enough address space for large partitions.
As for benchmarks, I think the answer is "don't ask".
No, Stallman is pushing this thing because its modular and relies on the Mach microkernel and the Flux OSKit library, in stark contrast to Linux's monolithic kernel design. Not to say monolithic kernels are bad, but microkernels do have their advantages, and both GNU/Hurd and GNU/Linux will each have their respective pros and cons.
"The lesson to be learned is not to take the comments on slashdot too literally." --Vinnie Falco, BearShare
Well, if you want to start that arguement.
Linux has nothing to do with Gnu. If you wanted to, you could make an OS using the Linux kernel & the BSD tools.
So, it's now the distros (e.g. RedHat) that are supposed to start throwing GNU in there. Of course, that would cause some user confusion when they go searching for this "GNU Linux" kernel.
Where does it end? What percentage of an OS's software has to come from a certain source that it must be included in all titles? Shall we call it RedHat Linux/GNU/XFree86/KDE ? Hey, the Gnu tools are replacable... XFree86 doesn't have any real competition, and so it more important than GNU.
What's that you say? rms is just a vain blowhard that will suck up publicity where ever he can get some? I'm sure he would disagree with that completely, and then go and complain about bitkeeper some more.
Man am I glad BSDs are better. In fact, rms thinks so too. Why else would he run FreeBSD on his server?
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
HURD is the kernel designed by the FSF, the people who made all of the GNU tools you and I use on Linux. It is architecturally different than all other Unix kernels in existence. Older Unix kernels are all monolithic kernels (ie, they are in a single file, vmlinuz on Linux). HURD runs servers that communicate with each other to do the functions that the single Linux kernel does. Go to the HURD website and read one of the technical docs, they are very helpful.
Slashdot is a waste of time. I enjoy wasting time.
That port is fairly extensive, so right now they're moving to Mach + OSKit, since OSKit supports the Linux 2.2 device drivers, something Hurd is sorely lacking.
It's a really hard problem to fix.
The ext2fs implementation is actually a userland process which takes a partition as an argument and attaches a translator to the mountpoint. The translator's job is to send requests under this namespace to this server.
The ext2fs server actually mmap()s the partition containing the filesystem and performs all operations as if it were a contiguous block of memory. Unfortunately the ext2fs driver, since it's a userland process, can only address 2GB of memory (the kernel often takes half). Adding a heap and a stack leaves mmap() with about 1GB to safely play with.
Eliminating this limitation would mean using either a 64-bit architecture, or using a read/write/lseek interface instead of mmap, which may mean totally throwing out the ext2fs server as-is. Perhaps they weren't concerned with the limitation because they thought everyone would be using 64-bit architectures by now?
I'm not sure if there are any other reasons other than the filesystem servers using mmap() for the limitation.
Actually, when distinguishing between implementations of the Hurd on different microkernels, we ususally say Hurd/Mach versus Hurd/L4. This is consistent with GNU/Linux and GNU/Hurd, ie. HigherLayer/LowerLayer.
OSKit-Mach is just a superior implementation of Mach, so we'd still call it Hurd/Mach if we needed to make a distinction.
Real improvements to the Hurd will come with the eventual port to the microkernel which is much superior to Mach (and the answer to current anti-microkernel FUD).
#define sig "Every social system runs on the people's belief in it."
Not true, friend. There are alternatives even to the GNU C library for those who object to RMS's politics.
And whether or not one uses the GNU C compiler is irrelevant. Code compiled with GCC is not part of the GNU project, nor it is required to be licensed with the GNU license. If you prefer, though, you can use Intel's C compiler, or Metrowerks's, or whichever compiler will work with your target architecture.
And you're mistaken about one more thing. The reason people drop the "GNU/" part of the name "GNU/Linux" is because "Linux," as has been pointed out again and again here by a persistent AC, is a registered trademark. Calling anything "GNU/Linux" without Linus Torvald's permission is infringement, and it's illegal. The name of the operating system is "Linux," and unless Torvalds says otherwise, that's the end of that.
I write in my journal
microkernels were the rage. HURD answered the call and started work. Now, almost 20 years later, MIT pulls the rug out with exokernels. So will we wait until 2020 to get a working model of that too?
God bless HURD for trying to advance the state of the art and improve upon the dated UNIX model, but sheesh! I wish HURD were ready for prime time. I really do. But a working model with caveats (Linux, OSX, *BSD) will always be better than a better model that's mostly theoretical in the real world.
That said, no one's paying the HURD developers. If it gos their nads, have at it. RMS needs to relax and realize that it is little more than a research experiment and not the second coming.
- I don't need to go outside, my CRT tan'll do me just fine.
Try:
MkLinux and
Mac OS X
Of course, both are somewhat more successful than the HURD...
STOP . AMERICA . NOW
Linux kernel has taken off in a very short time (about 10 years).
Try two years maybe less. Seriously. People were doing real work in a Linux environment running the version 0.99.x kernels which were release in 1993. Linux ran X, vi, emacs, and the GNU tools. For a lot of acedemics on a limited budget this was more then enough.
That never happened, did it?
Yes, it did.
http://www.tlug.jp/docs/linus.html
And what gives Linus Torvalds the right to say what the name of the OS is?
The United States Patent and Trademark Office.
Nope. That gives Linus Torvalds control over the word Linux. It doesn't give him any right over what the name of the OS is, if it doesn't include Linux. If it does include Linux, then GNU/Linux is as good as Red Hat Linux or Corel Linux; Linus has given explicit permission for all those names.
So Torvalds, who has exclusive control over the name "Linux," as used to describe computer operating system software, initially granted permission for the use of the name "GNU/Linux," but he and Stallman had different ideas of how that variation on the "Linux" trademark was to be used. In this interview, Torvalds makes it clear that he does not approve of the use of the mark "GNU/Linux" to describe "'every' Linux system." Consequently, the name "GNU/Linux" is an infringement on Torvalds's trademark.
If you want to call the operating system "Foonix," you're free to do so. You can call it whatever you want-- to the extent that you don't violate anybody's copyright. But you can't dilute or otherwise distort the trademark "Linux" without permission, which Torvalds explicitly denied in that interview.
Thanks for pointing out that article. It makes the issue even more crystal-clear to me.
I write in my journal
GNU/Hurd. 19 years in the making, and worth every minute of it.
That's not entirely fair. A lot of Linux-based OSes contain very healthy doses of GNU software and are compiled with GCC, one of the first major contributions of GNU.
The kernel was one of the last things they tackled, but along came Linus Torvalds and now many OS kernel developers would rather work on Linux than the Hurd.
Look at QNX and L4 as examples of fast microkernels. About all the kernel does is manage memory, interprocess communication, and task switching. Everything else is in user space, where it's easier to debug and can't mess up as much when it breaks.
In addition, if you're serious about security, a system where only the microkernel is trusted is the only thing that has any hope of working. In a microkernel system, the kernel tends not to change much over time, once it's working. New functionality is all in user space. You're not patching holes forever, like we are now.
You do take a performance hit, but in a world where Java, Perl, and XML are used for production work, it's tiny by comparison.
You're totally misinterpretting Mr. Stallman's beliefs about naming.
The free operating environment he has been trying to create for 20 years is called GNU. This encompases a kernel, userland, system libraries, compilers, etc. It's a whole, big lot of work. They started out with the editors, a C library, and a compiler so they could write the rest, and they went very far. GNU userlands started to supplant the traditional ones on most UNIX machines because GNU applications were full featured and matured quickly (try the BSD userland sometime, you'll start to notice missing options quickly), and because they were open and free.
But their kernel, the Hurd, lagged in development. Linus took the amazing GNU userland and added his Linux kernel. The GNU/Linux system was born, a fusion of the GNU userland and the Linux kernel. Mr. Stallman believes than Linus deserves much credit for bringing a free kernel into the world (remember, it was released when BSD was dealing with much legal ramblings), and that's why it's listed as a part of the name (and not just included in the name "GNU").
A modular layer deep in the kernel which can be swapped at will is not really relevant to it. You could ask why XFree86 is not in the name of GNU/Linux, and you'll be told it's because only the GNU and Linux parts were designed towards the goal of a free system. XFree86 is just a reference version of X11R6 which runs on x86 (and other) hardware. The same can be said of Mach, it's just a reference implementation of some software.
GNU is the only operating environment designed to be free as in freedom from the very start, which is why Mr. Stallman asks that you properly credit the GNU contributors for their many man-centuries of effort.
--
Internet Explorer (n): Another bug -- that is, a feature that can't be turned off -- in Windows.
So these days I just tell people to call it just plain "Linux" and nothing more.
That doesn't mean he sues people who don't call it just Linux; that means he encourages people to call it just Linux.
Torvalds explicitly denied
The normal way to explicitly deny use of a trademark is through your lawyer.
Consequently, the name "GNU/Linux" is an infringement on Torvalds's trademark.
And as I mentioned before, Debian GNU/Linux has existed for six years, with Torvald knowing about it. To this day, SPI has failed to get a letter from Torvald's lawyers about the issue. Letting someone use your trademark in business for years with your full knowledge is not what you do if you mean to specifically deny that use.
Honestly, I'm not sure the Linux trademark is valid anymore. I'm not familar with any attempt to police the mark, and there's a million different distributions called Linux with no quality control, which are two major issues in keeping a trademark.
No, what they're trying to do is offload the cache management to the virtual memory manager. With mmap() backed by the partition itself, the VM can read and write the pages transparently w.r.t the ext2 server. With read/write/lseek, you have to do actual memory management. Last time I looked, there was no interface for collaboration between the VM and the servers for cache management.
And this kind of cache management is horribly hard in a monolithic kernel for a start. Look how long 2.4 took before the VM behaviour was considered decent (2.4.16 iirc). A decently fast distributed one is even worse to design.
OG.
There comes a time when you have to cut your losses. HURD is a project that has gone seriously wrong. Mach development ENDED in 1994 (http://www-2.cs.cmu.edu/afs/cs.cmu.edu/project/ma ch/public/www/status.html)
There's nothing intrinsically wrong with microkernels or message passing (assuming you use zero-copy mechanisms and avoid contect switches) and they do provide excellent discipline to the design process.
The FSF is also modifying the GNU General Public License (GPL), though the fundamental principles will remain unchanged, according to Stallman.
"We have looked at, for example, adding a clause that explicitly states that you give a patent license when you redistribute the software," Stallman added.
This will hopefully remove some incompatibilityies between the GPL and other free licenses such as the IBM Public License 1.0 used for Eclipse.
I'm reading a lot of misinformation. First of all, THE HURD IS NOT A KERNEL! The HURD standards for Hird of Unix Replacing Daemons, wherein Hird stands for Hurd of Interfaces Representing Depth (a mutually recursive acronym according to the FAQ). The HURD is a bunch of servers that provide services around a microkernel. The revolutionary thing about it is that many of the traditional "kernel" tasks are moved into userspace. Result: the users are empowered. Why should mounting directories, shring NFS volumes, etc, require root? Normal users can use devices and network resources that previously only the administrator could control. For example, a normal user couldn't share the / volume, but he could share his home directory over the network, or mount a remote FTP site as a local folder in his home directory. (Yes, I did say mount FTP, HURD has some exciting new features like FTPFS, HTTPFS, etc, because so much of the implementation is left to the servers rather than the kernel.) Also, security is better, rather than root being the default access level, the default is guest priviledges, so priveledges start at none and are "tickets" are issued as credentials are elevated. Also, the Unix everything-is-a-file is taken further, where everything is part of the filesystem, including servers, etc. The HURD is a thing of beauty, and unless you've seen it down't knock it. I have a HURD test box on my LAN and it's running X with IceWM, Apache, FTP, NFS, etc. With some sound drivers and a complete pthreads implementation (which was just released), it could function as a workstation too. I don't see why we have to fight over Linux VS Hurd! Why can't we have both and pick the right tool for a specific job. I mean, we're the winners here, because the HURD gives us another *CHOICE*. It's about more freedom! So don't knock the HURD, most of the work is being done by a few programmers, Marcus Brinkman, Neal Walfield, and Thomas Bushnell. If Linus hadn't had the help of an army of developers where would Linux be? So give these guys their credit and realize that their efforts are giving you more freedom!
"As flies to the wanton boys are we to the gods; they kill us for sport." - William Shakespeare, King Lear
~Christopher Doopov