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LinuxWorld: Stronger I/O & VM Coming Soon to Linux

Posted by timothy on from the what-does-this-guy-know-anyhow dept.

Mark Brunelli, News Editor writes "Tim Witham, CTO of Open Source Development Labs and a featured speaker at LinuxWorld, says the next Linux kernel will feature improved input/output and virtualization capabilities. Said Witham: 'Enabling virtualization is a big win [for Linux 2.6] as it allows IT shops to start their development cycles for a technology they will be looking at deploying within the next year or so. There has been lots of good work done with regard to system scalability, memory management, disk I/O, process and thread scalability. Also, work done for availability, like a greatly improved multi-path I/O [were victories].'"

37 comments

  1. Content-free by interiot · · Score: 4, Informative

    Since the linked article seems to no more information that what the summary says, here's another link that discusses virtualization+kernel a little more. It looks like it's the Xen work that's going into the kernel (the project that IBM and AMD and others have been putting money and developers into to get working).

  2. Terrible title by SlashEdsDoYourJobs · · Score: 2, Interesting

    'VM', in the context of the Linux kernel, refers to its virtual memory manager, not virtual machines. It's incredibly misleading to read about 'stronger VM' like this.

    Wasn't usermode Linux integrated into the 2.6 kernel anyway? What improvements in virtualisation is TFA referring to? It seemed remarkably short on details.

    1. Re:Terrible title by ComputerSlicer23 · · Score: 2, Insightful
      VM refers to both, just depending on the context. While I agree with you I generally think of VM as Virtual Memory, not as Virtual Machine, it's just one of those things. For the first six months they talked about UML and getting it integrated into the kernel, I thought they were talking about "Unified Modelling Language". Just get over the title. Your initial assumptions and intuition misled you. Shocking.

      User Mode Linux is in 2.6, however, I believe they are referring to "Xen" which is a separate "arch" (like PPC, x86, SPARC). It is essentially an "arch" all it's own so that it can implement the low level details it needs to provide to the hosted OS's, but it has to run on top of a standard Linux kernel. It's an interesting concept.

      Kirby

    2. Re:Terrible title by jd · · Score: 2, Informative

      I believe they're referring to Xen, which can virtualize (in theory) any OS - not just Linux - and is (reputedly) considerably faster than UML.

      --
      It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
    3. Re:Terrible title by stevey · · Score: 2, Insightful

      No Xen cannot virtualize/host any OS.

      Instead the OS must be modified to support it. If you look at the Xen homepage you'll see more details.

      Whilst this doesn't diminish the usefulness of the project it does mean you cannot host an XP installation - like you can with Qemu , or the commerical software VMWare.

      I have used Qemu extensively in the past to host installations of Windows upon my Debian machine - whilst it is not as fast as Xen promises to be it is the best around at the moment (short of spending cash!)

  3. How does this affect me? by Anonymous Coward · · Score: 1

    What does this mean to a typical home user?

    1. Re:How does this affect me? by Anonymous Coward · · Score: 0

      For the home user, its another cool feature that you will never need. Linux is succombing to the "creeping feature" blight just like Windows. Instead of getting the stuff that's already there working properly, the developers are instead trying to make the kernel more buggy and bloated.

      How about:
          cut and paste between apps
          unified management framework
          better network utilities

  4. What's with Linux and Disk blocking anyway? by bill_mcgonigle · · Score: 3, Informative

    What's the deal with disk I/O killing the responsiveness of the system anyway? When you have to move monstrous amounts of data, a Linux system can get practically unusable, no matter which user is initiating the load.

    I used to think this would go away with faster machines, or the interrupts would be freed by using SCSI HBA's, but the symptoms still persist today, even on a modern 'fast' machine.

    I never experienced anything like it on, say, Sun hardware, in the pre-Linux days.

    --
    My God, it's Full of Source!
    OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
    1. Re:What's with Linux and Disk blocking anyway? by gid · · Score: 2, Interesting

      I agree it's annoying, even using a pre-emptive kernel doesn't seem to help much anymore, although I swear it used to.

    2. Re:What's with Linux and Disk blocking anyway? by oliverthered · · Score: 2, Informative

      And I've just spent the last 6 months trying to find out what's hanging on to that IRQ and blocking everything else..

      DMA should stop this from happening (I wonder if it happens outside X86)

      --
      thank God the internet isn't a human right.
    3. Re:What's with Linux and Disk blocking anyway? by bill_mcgonigle · · Score: 1

      Any luck? I'd suspect someone on the lkml knows what it is.

      --
      My God, it's Full of Source!
      OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
    4. Re:What's with Linux and Disk blocking anyway? by oliverthered · · Score: 1

      I think it's the DVD drive, a memory upgrade made most or the problems go away (I don't hit swapspace any more!) I'm waiting until I upgrade my PC and then may have a look as running some diagnostics (and turning on kernel debugging etc..)

      --
      thank God the internet isn't a human right.
    5. Re:What's with Linux and Disk blocking anyway? by allanc · · Score: 1

      Yeah, I don't want to start a holy war here, but what is the deal with you Linux fanatics? I've been sitting here at my freelance gig in front of a Linux box (a PIII/750 w/64 Megs of RAM) for about 20 minutes now while it attempts to copy a 17 Meg file from one folder on the hard drive to another folder. 20 minutes. At home, on my PowerMac 8600/300 running OS9, which by all standards should be a lot slower than this linux box, the same operation would take about 2 minutes. If that.

      (This post is a joke, incidentally)

    6. Re:What's with Linux and Disk blocking anyway? by Anonymous Coward · · Score: 0

      Get more ram.

    7. Re:What's with Linux and Disk blocking anyway? by NullProg · · Score: 1

      I backed up my 2 gig $home directory to another partition in under ten minutes (using tar + cp). Were you using GUI file manager to copy the 17meg?
      I find even file manager slower under windows vs xcopy.

      Just curious,
      Enjoy.

      --
      It's just the normal noises in here.
    8. Re:What's with Linux and Disk blocking anyway? by NullProg · · Score: 1

      I noticed this when I switched from 2.4.x to 2.6.x kernel (Now running 2.6.8-24).

      When I cp a 2+gig file to a different partion (ext3 to fat32) the system acts sluggish and I can't play games or compile with any responsiveness. It could be the filesystem layer, but I don't buy it.

      When I burn a CD iso (XCDRoast), I have no responsiveness problems playing Cube/Privateer or anything else. Go figure.

      Its still better I/O than Windows though. Install Open Office from a windows share, install an another application from the CD RIN and copy some big program from the floppy. Windows locks up everytime (OS/2 passes and so does Linux).

      I'm using all IDE drives here. I haven't tried this with SCSI or SATA yet.

      Enjoy,

      --
      It's just the normal noises in here.
    9. Re:What's with Linux and Disk blocking anyway? by Anonymous Coward · · Score: 0
      YHBT. YHL. HAND.

    10. Re:What's with Linux and Disk blocking anyway? by Anonymous Coward · · Score: 2, Interesting

      The simple answer is Linux uses write-back caching, and will let a process write data faster than it can actually be sent to the disk, thus filling up all the available memory pages and blocking other I/O.

    11. Re:What's with Linux and Disk blocking anyway? by weicco · · Score: 1

      You got something wrong in your Windows. I'm copying ~10 gig Virtual PC file to another drive and writing this message, playing MP3 from same drive I'm copying (with MWP), using SSH-client and even compiling C#.NET application at the same time. No responsiveness problems, no locking-up or anything. I don't have floppy drive attached so I can't try what it would do, but copying from DVD doesn't cause any problems. Maybe your hardware is broken?

      --
      You don't know what you don't know.
    12. Re:What's with Linux and Disk blocking anyway? by allanc · · Score: 1

      Please reread the last line of my post.

    13. Re:What's with Linux and Disk blocking anyway? by wild_berry · · Score: 2, Insightful

      Shouldn't the kernel tell the task to slow up when you're getting toward 2/3 (or 50%, 75%, 80% etc.) of the available memory pages? Would boot-up tests that store data-rate metrics for the available storage allow the system to slow down tasks likely to fill the memory pages before the disks can catch up which would allow the system to retain 'teh snappy'?

    14. Re:What's with Linux and Disk blocking anyway? by Sensible+Clod · · Score: 1

      Or, indeed, maybe hardware driver is broken...

      --

      The difference between spam and poop is that you don't have to dig through septic tanks looking for real food. -- Me
    15. Re:What's with Linux and Disk blocking anyway? by NullProg · · Score: 1

      You got something wrong in your Windows.
      Why would you say that? My Windows (2000) is lean and clean. My hardware is also different from yours.

      I'm copying ~10 gig Virtual PC file to another drive and writing this message, playing MP3 from same drive I'm copying (with MWP), using SSH-client and even compiling C#.NET application at the same time. No responsiveness problems, no locking-up or anything.

      Im also running a PIII with 256 Meg of RAM. Are you? I didn't buy this computer with the intention of running Anti-Virus or Ad-Aware programs. You are running both. Your not excerting any kind of interrupts. Try using more than three at the same time.

      Your not compiling anything. Your assembling the source into bytecode for the VM (CIL/ILM). But go ahead and make yourself look important. Will your program work under AIX? StrongARM? Linux? Nokia? I'm looking forward to meeting a real "computer programmer" who states thier code only runs under windows.

      Enjoy

      --
      It's just the normal noises in here.
    16. Re:What's with Linux and Disk blocking anyway? by weicco · · Score: 1

      Okay, your hardware is little old and you're using W2K. That explains a lot. I have AMD 2600+, 1.5 GB RAM and Windows XP. I'm not running Anti-Virus or Ad-Aware programs. Well, I've checked my computer couple of times for viruses and found absolutely nothing.

      My program works on Linux, FreeBSD and Windows without ... reassembling it (is that the correct word?). I don't know if assemblies are portable across different processor architectures, but I guess it runs on StrongARM also (Windows CE). I've never used AIX and so haven't 99% of rest of the world, I couldn't really care less for it.

      But Nokia... That's intresting. I didn't know that Nokia makes operating systems. Maybe you meant Symbian? Well, Symbian is so full of crab that I refuse to work on it anymore. Two years of Symbian C++ (my god, they have even twisted C++) was enough.

      --
      You don't know what you don't know.
  5. May be what the Linux community needs by thatedeguy · · Score: 1

    An added bit of usability and stability to an already stable and usable system can't hurt in the war on microsoft.

    --
    A Linux flavor for every Month!
    1. Re:May be what the Linux community needs by cant_get_a_good_nick · · Score: 2, Interesting

      Not sure if that was a real post or meant to be humor, but mucking with the VM is not the way to be more stable. There were major stability issues in the early 2.4 kernels due to the new VM that was swapped in. My company is still dealing with bugs in what can be seen as a VM issue - the 4Gb user/4Gb kernel split in RedHat advanced server, and this is in the new U5 update.

    2. Re:May be what the Linux community needs by cant_get_a_good_nick · · Score: 2, Informative

      My mistake, article was (though unclear) talking more about Virtual Machines than Virtual Memory, I guess I'm too frustrated at having the occasional kernel panic...

  6. Some thoughts by jd · · Score: 2, Interesting
    Once virtualization is introduced into microprocessors, you will be able to run a real copy of Windows in parallel to Linux, using Xen.


    Improved I/O means home networks should run closer to the capabilities of the wire, plus multimedia on the computer is less likely to stall when playing. It may also make Linux more attractive to games writers, as a lot of games these days are heavy on multimedia.

    --
    It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
  7. Which next kernel? by Mad+Merlin · · Score: 1
    The article doesn't say which next version exactly that we can expect these improvements in. When I think "next Linux kernel" I think the next point release in the current version (in this case, 2.6.13), but these sort of sweeping changes seem awfully ambitious for such a short period of time, thus we should expect these changes in 2.8.0? But what happened to 2.8.0 not coming any time soon?

    Anybody know what they're talking about when they refer to "next Linux kernel"?

    --
    Game! - Where the stick is mightier than the sword!
    1. Re:Which next kernel? by Lemming+Mark · · Score: 2, Informative

      Xen support won't be in 2.6.13 but could be in 2.6.14. Basically the hold up is in restructuring to fit with emerging kernel policies on x86-like architectures (i.e. fit them into the i386 directory, instead of forking a separate arch tree as x86_64 did). Once this restructuring is done, the Xen patches should get merged.

  8. Also according to their info... by jd · · Score: 2, Informative
    ...once CPUs are capable of supporting virtualization directly (the next generation of Intel and AMD should do this), host OS modifications will not be required.


    So, whilst you are correct it cannot virtualize any OS on current processors, that is not quite the same as saying it can't virtualize any OS in the future, which is what I was referring to. Apologies on my part if I wasn't clear on that - I'm not always as clear as I could be.

    --
    It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
  9. Multipathing by superpulpsicle · · Score: 1

    Last time volume managers and raidtabs came out for linux, the market quickly flooded with too many mediocre flavors. I expect multipathing software to do the exact same.

    1. Re:Multipathing by Meetch · · Score: 1
      I'm hoping for better, as it's the only flavour of Multipathing that RedHat will support! Where I work we use QLogic's 2300 series HBAs - single adapters with dual paths for test, dual adapters with dual paths for production. They are very VERY sweet, and once you start playing with SANSurfer, you discover the power of SAN disk configuration that users of "big iron" would typically take for granted. The catch is, you need to install the vendor's HBA drivers (remember to fix RedHat's broken qla2300_conf module link, rewrite the HBA config to the module, and recreate your initrd!) and figure out how to configure the pathing optimally.

      The biggest downside is that, looking at the GPFS benchmarks in IBM's redpaper on intel clusters vs the virtualisable P series, clustering filesystems on intel hardware simply does not seem to scale I/O at all well compared to the high end equipment like IBM's P690 or 595, which are pretty close to linear.

      The other downside is that RedHat will not support it. But then RedHat also prefer you to boot off your lone internal IDE drive rather than off your SAN (which appears to be flatly unsupported).

      Yes, I will bitch about RedHat a bit, as I have had to deal with their support for some time now, but all in all IMHO they're still good for Linux. Hopefully they will pull through with building Enterprise quality generic multipathing support into EL4 through the dm and md...