Slashdot Mirror

← Back to Stories (view on slashdot.org)

Dynamic Logical Partitioning for Linux on POWER

Posted by Hemos on from the learn-how-to-do-more dept.

An anonymous reader writes "Logical partitioning provides POWER processor-based servers with the capability to do server consolidation and optimize system resources. Dynamic logical partitioning enhances this capability by providing control of the allocation of the resources without impacting the logical partitions availability. Linux on POWER supports dynamic LPAR for changes to physical I/O, virtual I/O, and processor resources."

17 of 111 comments (clear)

  1. droool... by dj245 · · Score: 3, Funny

    And for once I drool over something I have only vaguely an idea of what it does.

    --
    Even those who arrange and design shrubberies are under considerable economic stress at this period in history.
    1. Re:droool... by Amiga+Trombone · · Score: 5, Informative

      And for once I drool over something I have only vaguely an idea of what it does.

      What it does is allow reconfiguration of system resources, such as IO cards, memory or cpu's (or on Power 5 with AIX 5.3, portions of a cpu), etc. on the fly without having to reboot your server to acknowledge them. AIX has had this capability since 5.2.

      It's great for being able to juggle your resources on the fly, but it really comes in handy for moving your DVD drive between partitions on a frame without having to reboot. Having to reboot 2 servers just for that is a royal PITA.

    2. Re:droool... by Ryan+Amos · · Score: 3, Informative

      The POWER series has this on-chip, so it's a whole lot faster than doing it via software and it doesn't require a reboot. The dynamic partitioning is the real difference between the POWER series and the PowerPC chips IBM sold to Apple. This is a feature carried over from IBM's mainframe days, and if you actually need it, it is very cool.

  2. Cool, but still buggy by Kris2k · · Score: 4, Interesting

    I've worked on it on a few times, and its still a bit buggy, but IBM seems to never cease to amaze me by pulling-out new patches on a daily/weekly basis. With time, this technology will perfect itself, and when it will, it will really rock, for now, I'd still go with a BladeCenter + SAN.

    1. Re:Cool, but still buggy by Kris2k · · Score: 2, Interesting

      Oh, and an after-thought:

      Redundancy is achieved with multiple independent subsystems

      Well, in the case of LPAR, when your host OS decides to pull a quickie on you, you find yourself on a standstil with an entire company of 100+ users without their apps running. I wouldn't like to be in the shoes of the iSeries admin in that case.

    2. Re:Cool, but still buggy by atomicdoggy · · Score: 2, Interesting

      An LPAR doesn't have a "host" operating system. The partitioning is done in hardware (each LPAR has it's own installation of the operating system).

  3. Power Rocks by as400tek · · Score: 2, Interesting

    Then entire world will move to POWER in the next 10 years. POWER 5 is where it's going folks. Great IBM Hardware is paving the way for the great OSs of the world to run like champs. I have been an AS/400 now iSeries Admin for over 15 years and POWER/5 is awesome. Good to see some Slashdot coverage on the topic of POWER. IBM is still trying to figure out what to do with LINUX and maybe this is it. Will have to wait and see what happens next.

    --
    David Vasta iSeries(AS/400) Admin & Junkie
    1. Re:Power Rocks by imsabbel · · Score: 4, Insightful

      They told the same thing 10 years ago about powerpc, and look what has happened.

      Target market for Power(5): Servers. No mainframes (as those are a different area), no HPC (horrible FPU/$ performance compared to main competitors), no small servers (PPC970 is more or less dead in the water, and power5 with its horribly expensive MCMs isnt cost effective in the more "normal" enviroment.

      SO i _seriously_ doubt "the entire world" will be using power in 10 years. They can be happy if the keep their market share.

      --
      HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
    2. Re:Power Rocks by $RANDOMLUSER · · Score: 4, Funny
      > Then entire world will move to POWER in the next 10 years.

      I respectfully and completely disagree. The world enjoys using a 64-bit extension to the 4004 architecture. We like using a single-accumulator processor with 3 "general purpose" registers. We adore the massively irregular instruction set, we like saying "push bp/mov bp,sp" every four instructions. We like the whole notion of putting values in certain (and only those) registers, so we can say "repne scasb", or "mul" or "div". The segmented memory architecture and the segment registers, are, in a word, brilliant. The notion of "near" and "far" calls and jumps, and the fact that the segment and offset are pushed in the wrong order is an endless source of delight for us. The floating point unit, and its instruction set, are nothing short of poetry in silicon. The pipelining and branch prediction are the the epitome of efficiency.

      In other words, you are just another sadly mistaken fanboy of an inferior processor architecture.

      --
      No folly is more costly than the folly of intolerant idealism. - Winston Churchill
    3. Re:Power Rocks by DannyKumamoto · · Score: 2, Interesting

      "SO i _seriously_ doubt "the entire world" will be using power in 10 years. They can be happy if the keep their market share."

      With PS3, Xbox 360 and Revolution containing some flavor of POWER5 (Cell certainly has inherited POWER5 technologies), I'm pretty sure "the entire world" would have these powerful capabilities. Unlike workstations and PCs, these game machines won't be so hacker friendly but then I doubt if most people of "the entire world" would care less....

      --
      Danny Kumamoto
  4. Done for years by fiber0pti · · Score: 3, Informative

    This has been available from IBM for years. I've only started with POWER 4 but I think it was available a few versions back as well with limited functionality on Linux. The more advanced features recently came available with the release of the POWER 5 processor. Nearly all of the RAS features are now available for Linux on IBM that have been available for AIX.

    They also support Redhat and SuSE. Good stuff!

  5. wait till you figure out SMT! by mekkab · · Score: 3, Informative

    Simultaneous Multi Threading is an even cooler feature of the POWER 5 chip!

    Here's a pdf.

    --
    In the future, I would want to not be isolated from my friends in the Space Station.
  6. Tip of the iceberg... by vdthemyk · · Score: 3, Insightful

    This document just touches on the capabilities. If you want to see a little bit more detail regarding running linux LPAR's on a POWER 5 system, I suggest heading here.

    This is a good technology, and if there are people wanting to get LPAR capabilities without having to purchase all that extra IBM OS's (AIX, i5/OS), you might look into the OpenPower line. 2 way or 4 way POWER 5 systems that run only linux and can create upto 40 LPAR's on one system. That's bascially like having 40 different Linux servers all running at the same time on 4 total processors.

    I agree this technology has some limitations as of right now, but it may not be a bad idea to look at it. And remember, this is PPC Linux, not your standard Intel Linux. While your boss won't know the difference, you should.

    --
    VD
    1. Re:Tip of the iceberg... by digitalhermit · · Score: 2, Informative

      It's a pretty cool technology. We're running multiple AIX 5.3 partitions on IBM pSeries boxes. Setup of the systems are pretty easy and allocating memory/CPUs is straightforward. The only concern is that the overhead increases substantially with the number of LPARs.

      The only problem I have with pSeries linux is that it somewhat negates the cost advantage of Linux on Intel. Well, make that obliterates the cost advantage. IBMs AIX is free with the hardware. Linux is licensed per instance. So it's cheaper to run AIX *on pSeries* when you have many instances.

  7. Xen by SumDog · · Score: 2, Interesting

    This type of technology has been available from IBM for years. I remember those old AS/400 machines during my undergrad that had removable boards that you could hot swap which contained extra processors. One of my professors told me about when he took operating systems, he made his OS on an IBM machine and was able to use one of the six processors available in his own little virtual space without interfering with anyone else's simulations.

    Correct me if I'm wrong, but this seems like IBM has placed into hardware what systems like Xen currently does in software, allocating virtual space for different operating systems to share resources and execute simultaneously.

  8. Still no support for Dynamic Memory by The+Mad+Duke · · Score: 3, Informative

    Nice write up from IBM, but it's important to remember thaat the Linux kernel only supports dynamic changes in CPU and PCI devices, you can't move memory around. AIX allows dynamic memory; the Linux kernel will need some fundamental chages to enable this. Power5 is indeed the coolest technology around today, but Dynamic LPAR started on the Power4 back in 2001, so this is kinda old news.

    --
    -The Mad Duke
  9. LIcensing? by Necron69 · · Score: 2, Interesting

    I found this interesting. Try this on the bits for the RHEL4 packages:

    for i in *.rpm; do rpm -qilp $i |grep -i license; done

    Size: 2547252 License: IBM Corp.
    (lots of output deleted)

    11 "IBM Corp." licenses.
    1 IBM Common Public License (CPL)
    1 GPL

    Open Source it ain't. I'd rather use Xen.

    - Necron69