The Black Liszt

Tag: storage

  • Mainframes and Storage blades: Xiotech’s ISE

    In computing, the transition from mainframes to blades is
    well established. What about storage? There is exactly one choice: the Xiotech
    ISE.

    We throw words around like crazy in computing. Once a word
    starts to become associated with something good, every person in marketing in
    the universe latches on to that word, and finds a way to associate it with
    their product. Most of the analysts aren’t much help here.

    The opposite applies, too. Once a word is no longer in fashion,
    no vendor admits to selling it, and no buyer admits to owning one. A case in
    point is “mainframe.” Some time ago, you had to have a mainframe to be in the
    big leagues of computing; otherwise, you were in the minor leagues, dealing
    with unimportant problems. Now, even though mainframes are alive and well and
    broadly used, it’s hard to get anyone to admit it. “Everyone” knows that
    mainframes are old-fashioned.  

    In spite of their un-cool-i-tude, let’s talk mainframes for
    a quick minute. What’s a mainframe? In computing, it’s a big single thing that
    gets all of many big jobs done at the same time. It is your central computing
    resource. It’s valuable. It takes lots of time and attention to manage, but
    rewards the attention by being the work-horse of your data center. As your
    workload grows, your mainframe can start to get overloaded; no problem.
    Capacity measurement and planning is a key skill with mainframes, and even
    better, mainframes are built to be expanded. That’s why they’re called “main
    frame.” It isn’t the CPU – it’s the frame (the main one!) that structures your
    computing engines. Sometimes your mainframe needs more compute-power; no
    problem, you can add it in. Sometimes your mainframe needs more I/O channels
    or local memory; no problem.

    What’s cool today, if not mainframes? We all know the
    answer: it’s racks and racks of servers or blades. Each one is powerful but
    inexpensive. You increase capacity by buying more of them. That’s why
    virtualization is such a powerful trend in the data center: VM-Ware (and
    similar products) helps you use all those servers more efficiently. Everyone
    has lots and lots of servers; therefore, the need to use them as effectively as
    possible is ubiquitous; therefore, Hyper-V and its brethren are hot.

    What’s going on in the world of storage? Do we have storage
    mainframes? Of course not! Heaven forfend! “Mainframes” are the bad old,
    un-cool thing, so there’s no way my storage is a mainframe – it’s a SAN, a
    storage area network! It’s a network, see, it’s cool!

    Now let’s cut through the verbiage, and apply the criteria
    of mainframe to storage. A mainframe (see above) is:

    • A big single thing that gets all of many big storage jobs
      done at the same time; check.
    • Your central storage resource; check.
    • It’s valuable; check.
    • It takes lots of time and attention to manage; check.
    • Capacity measurement and planning is a critical function;
      check.
    • You expand capacity by augmenting it, adding things into it;
      check.

    There’s a simple rule here. Suppose you buy a “small, simple”
    mainframe. When you’ve added huge amounts of capacity to it, how many do you
    have? If the answer is “one,” you’ve got a mainframe. If you’ve got a small,
    simple server/blade collection, you’ve already got a bunch of them. When you’ve
    added loads of capacity, you’ve got loads more of them. You’ve never got just
    one. You start with some, you grow to lots, and expand to lots and lots.

    Applying our rule to storage, it is undeniable that while vendors
    will avoid the “m-word” like crazy, what they’ve all got is storage mainframes.
    They are single things, just like a railroad train is a single thing regardless
    of the number of engines at the front or freight cars at the back. Even if they
    choose to call it “cloud storage,” the brutal fact is that it is still a
    monolithic, single, unbroken entity – a mainframe, in short!

    There is exactly one vendor in the market who has created
    for storage what blades are for computing, and that is Xiotech, with its ISE
    product. You do not expand an ISE; you buy another one. Each ISE is a separate,
    free-standing, inexpensive but powerful resource, directly connected to a
    switch – just like a server.

    The Xiotech ISE is the anti-mainframe, and is the
    natural choice for server-farm data center storage.

  • Xiotech and the Strange World of Storage Administration

    Storage administration is a world of its own, controlled by storage administrators, running by their own set of rules. It's got to stop!

    Not entirely, of course. Storage is a specialty, and it definitely rewards having someone really know all about it.

    Think about it from an application programmer's point of view. What if files had the same rules as storage? Instead of just adding a "create file" statement to your program, you'd have to request one from the "file administrator," who may give you one after talking with you. You would agree on the name. You would talk about how big the file would get, and how often you intended to access it.

    If everything went well, you would each go off to your respective domains, enter exactly the same information into your respective systems, and the file would be available. It would almost certainly be created before you needed it (better that than after you needed it!), and be set up to give you ample space.

    What would be the net result?

    • You and the "file administrator" would spend more time setting up files.
    • There are more opportunities for mistakes and mis-communications.
    • The files would be set up longer than needed, and possibly larger than needed.
    • They wouldn't be deleted automatically by your program — the file administrator would need to be notified.

    In other words, the situation would be worse in just about every possible way. More time, more chances of error, less automation, more resources used longer than necessary.

    Fortunately, this was a hypothetical for files. We have language-specific versions of "create file" and "delete file," so that applications can control their own lives, and programmers can program and be done with it.

    Unfortunately, this is daily reality for storage! Bummer! Why shouldn't applications be able to control storage the way they do files? This may not matter much for persistent storage that doesn't change much, but it matters hugely for storage that is used on a temporary basis. Most places that I've looked at don't think about it any more. Why should they? They just over-provision like crazy and be done with it. 

    This situation changes the second you've got a simple set of API's you can call from scripts or applications that do for storage what we already know how to do for files. This is a capability all storage vendors should provide. Can you guess which one of my favorite storage vendors has a real story on this subject? Good, check it out…

    Actually, just going to their website isn't enough (for now), since the RESTful API for storage administration is still in advanced beta. But it's real, it's cool, I've seen it, and they're even starting to admit its existence, per Brian Reagan:

    CTO Steve Sicola detailed the Q1 and Q2 roadmap, including CorteX
    (coming in Q1) – Xiotech’s RESTful API that will allow developers
    simple yet powerful access to ISE.

  • Old Nerds at Xiotech

    Xiotech has some amazing old nerds. See descriptions here and pictures here.

    Most nerds who entered some computer-oriented field in the 1960's (like I did) gradually figured out that being a nerd was the best way to do most of the work and get the least of the credit, money and appreciation. So they wised up, dressed up, cleaned up and moved up the management hierarchy.

    Of the remaining nerds, most kind of drifted along being role players, fulfilling some incredibly narrow function.

    But some nerds were so strong, so self-motivated and so, well, nerdy, that they marched along actually doing real work, solving new problems, and creating products that changed industries. They didn't deny their inner nerdiness. They were proud of it during the days when it wasn't something to be proud of.

    One of the many amazing things about Xiotech's CTO, Steve Sicola, is that he is a world-class "nerd herder." Now that he is aided and abetted by the terrific Xiotech CEO, Alan Atkinson, he has been able to attract an amazing group of wildly productive and experienced nerds.The ones pictured on the web site aren't the only ones, either! Just to name a couple, there is Todd Burkey, Randy Roberson, Marshall Midden, Mark Rustad, and even that isn't everyone.

    This isn't just of historical or sociological interest. Old nerds of this kind, when given resources and focused on a juicy business problem, can conceive and build better products, more quickly and efficiently, than whole departments of well-qualified engineers working at established companies. It's like everyone else has a bunch of beginners at chess, organized and led by a bunch of chess "managers" (what a concept!), while Xiotech has an elite team of energized and focused chess grand masters. The rest of the world is hopelessly outclassed.

  • Computer Storage’s Performance Gap

    There is a growing "performance gap" in computer storage due to basic physics, and exacerbated by server virtualization. People who run data centers see the problem, and so do their customers. It gets worse every year.

    Most storage vendors have no real solution to this problem. Xiotech, with its ISE product, is a notable exception. For this reason (among several others), Xiotech is one of my favorite companies.

    The Performance Gap

    In a nutshell, the "performance gap" is that as disk-based storage gets less expensive, the rate at which any one customer or user can get at their data gets worse and worse. Capacity goes up and performance goes down, resulting in a performance problem. Seems strange, doesn't it? Doesn't everything about computers get faster, smaller and cheaper? What's this about something getting worse all the time? Well, it's true.

    As everyone knows, computers get faster and less expensive. As they get faster, they read and write data more quickly. Storage that is built out of the same electronic "stuff" as the computer (RAM, DRAM, the "main memory" of the computer) gets faster and less expensive at pretty much the same rate as the processors. No problem there. But what about the disks (hard disk drives, HDD's)? Do they get faster and less expensive too?

    Well, that's the problem. They do get less expensive — that's part of why we have iPod's and digitial cameras now. But they do not get much faster. Mostly what happens is they hold more data and get physically smaller.

    A dozen years ago, you could have bought a HDD that had 10GB on it. Today, you can buy HDD's that are physically smaller that hold over 1TB. For less money!

    Smaller, more capacity, less expensive. What's wrong with that? Imagine that you have 1TB of data. A dozen years ago, you would have stored it (ignoring details like overhead and extra space) on 100 HDD's, each holding 10GB. Today you would only need one HDD — a 100:1 advantage! That's the good news.

    The bad news is that a dozen years ago, you would have had 100 HDD's, each with a head and data channel to read and write your data, while today you would have a single read/write head to access the same amount of data. This is 100 times worse than it was a dozen years ago! It's like Yankee Stadium with the same number of fans, only locking all the entry gates except one; do think there would be a line at that single door?

    If banks operated the same way with ATM's the way drive vendors do with HDD's, here's what it would be like. The bankers figure they're going to put a certain amount of cash in ATM's for the citizens of, say, New York City. Each year, new ATM's become available that can magically store a lot more cash in less space at lower cost. Of course they go to town, replacing each couple of old ATM's with one double-capacity ATM. They're feeling good about themselves — they've made the same amount of cash available to their customers while lowering their costs.

    Suppose that ten years ago, their were 100 ATM's in NYC. With this incredible technical growth in ATM's, the bankers can make the same amount of cash available using just one ATM — isn't that great?!

    Of course, the problem is obvious. People don't care about how many ATM's it takes — they care whether there's an ATM near them when they need cash, and whether there's a line of people waiting for access to that ATM. Imagine the impact of reducing the number of ATM's by a factor of 100. The same amount of cash is in the remaining ATM's as before, so the capacity is not reduced, just the number of access points.

    That is the performance gap: the same amount of "stuff" is crammed into a tiny fraction of the number of "boxes," but the "doors" to the few remaining boxes are no larger.

    Fundamentals: Physics vs. Electronics

    Hard Disk Drives (HDD's) contain one or more little platters (kind of like small CD's) that spin in a sealed enclosure. The platters spin, and as they pass by the read/write heads, data may be written or read. Here is a basic summary of HDD technology, with diagrams.

    Every year, vendors manage to make the little platters even smaller, make the read/write heads able to handle "bits" that are smaller and smaller. More data gets crammed into less space.

    The trouble is that the platter can't spin much faster than it already does. If the data you want is on the other side of the platter from the head, you still have to wait for the platter to spin around — and that takes the same time as it did when there was 100 times less data on that platter.

    In addition, platters (like CD's) put data everywhere, from the small inner part to the larger outer edges. With a single head to read or write, the head still has to be moved to the right place (this is called "seek time"), and that movement isn't much faster than it was years ago. 

    Finally when you've got the "ATM" problem or the "Yankee Stadium" problem, the problem gets really bad — the chances that your data is on the same platter as someone else who wants their data at the same time has gotten 100 times worse.

    As the electronics of shrinking bits gets better, the performance gap gets worse, because physics doesn't let us move things or spin things way faster, and the simple arithmetic of cramming more data through the same-size door just blocks us.

    Server Virtualization

    Server virtualization is a major trend in data centers. It basically enables data centers to reduce the number of servers they use by using virtual machines instead of physical machines. With the help of software, applications that used to require dedicated machines can share a smaller number of physical machines. 

    This is generally a good idea and saves money. Except for this little problem about storage. By putting multiple applications on each server, the number of read/write requests coming out of each server has just gotten larger. Which makes the storage performance even worse. Ughh.

    Conclusion

    Advances in storage technology are paradoxically making storage performance worse. Server virtualization, while generally a good thing, exacerbates the problem. How do you solve the performance gap? There are several major ways.

    • Buy enough HDD's to give you the performance you need. This may mean that you are way over-capacity, but who cares? Your users aren't trying to wring your neck because they can't get their data. And the extra money all that costs? Well, that's life.
    • Pay 10 to 20 times more per GB and buy solid-state storage (SSD's) — and change your applications to take advantage of it. Problem solved! The extra money and trouble? Well, that's life.
    • Buy ISE's from Xiotech. Buy only the capacity you need. Your users will love you and you won't have to touch your applications to make it work. The extra money and trouble? There is no extra money or trouble. That's life — the good life, that is.

    Am I proud to be associated with Xiotech? You betcha.

  • Xiotech’s ISE: A Revolution in Storage

    Xiotech is leading a revolution in storage: all the leading vendors are selling the storage equivalent of mainframes, while Xiotech is building the storage equivalent of blade servers. I'm proud to be associated with them.

    Xiotech calls its "storage blade" an ISE — intelligent storage element. Insiders frequently call it "the brick." I’ve
    tried to come up with the simplest possible thoughts for explaining an
    all-brick approach to storage.


    All
    SAN’s today are built from two basic things:

    1. Drive bays or trays. These are the units that actually
      hold all the data, and where all the drives are. They include power
      supplies, data connectors and logic boards to perform basic functions.
    2. Controllers. This is where the “intelligence” of the
      SAN is. The controllers are connected on the “back” side to the drive
      bays, and on the “front” side to servers and/or switches. As far as the
      servers are concerned, the controllers are the storage. They get
      requests from the servers and satisfy those requests by getting data from
      various drive bays. Data goes from server to controller to disk when
      written, and from disk to controller to server when read.

     

    The
    Xiotech innovation with the ISE is to build a new-age drive bay that contains
    all the essential functions of the controller, which are:

      • read and write my data;
      • don’t make me worry about individual disks;
      • keep it safe, even if a disk breaks

     

    So
    first of all, the Xiotech ISE is a drive bay with built-in essential SAN
    functions. But why stop there? If you’re going to concentrate on basics, really
    do it right. So the ISE goes way beyond SAN controllers and drive bays
    by adding these functions:

     

      • read and write my data really quickly
      • don’t make me become an expert to get great results
      • don’t charge too much
      • it won’t break, so don’t charge me for maintenance.

     

    It’s
    important to understand is that the Xiotech ISE looks like a drive bay,
    except:

    • It fits in 30% less space
    • It uses less power
    • It requires no maintenance
    • It performs better than other systems because of novel,
      built-in virtualization

     

    This
    supercharged drive bay, the ISE, gives you everything you need from a SAN, without
    a controller. Why is this good? Because dropping the controller:

    • Saves money
    • Results in a linearly scalable system
    • Eliminates the drag of features you don’t need

     

    Do
    some people really need controllers? Yes. There are some functions that are
    performed very well in controllers, and for those functions Xiotech has an
    excellent controller, and others are available from third parties.

     

    Do
    you need a controller? Here are the reasons you may not:

    • You use a server-based LVM to perform higher level
      storage functions
    • You want your application to control its own storage
    • You use blade servers, and would like the equivalent of
      blades for storage
    • You’re very concerned about performance, and you need
      linear scaling
    • You want to avoid storage experts and getting into the
      whole world of storage; you just want fast, reliable storage
    • You know about server virtualization, and you want
      storage that “fits in” to that style of computing
    • You’re cost-conscious about storage, including
      operating costs and maintenance

     

    Xiotech
    is pioneering a new approach to storage – what server farms are for servers,
    Xiotech ISE’s are for storage.Obviously, I think it's a winner.

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