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Tony Pearson is a Master Inventor, Senior IT Architect and Event Content Manager for [IBM Systems for IBM Systems Technical University] events. With over 30 years with IBM Systems, Tony is frequent traveler, speaking to clients at events throughout the world.
Lloyd Dean is an IBM Senior Certified Executive IT Architect in Infrastructure Architecture. Lloyd has held numerous senior technical roles at IBM during his 19 plus years at IBM. Lloyd most recently has been leading efforts across the Communication/CSI Market as a senior Storage Solution Architect/CTS covering the Kansas City territory. In prior years Lloyd supported the industry accounts as a Storage Solution architect and prior to that as a Storage Software Solutions specialist during his time in the ATS organization.
Lloyd currently supports North America storage sales teams in his Storage Software Solution Architecture SME role in the Washington Systems Center team. His current focus is with IBM Cloud Private and he will be delivering and supporting sessions at Think2019, and Storage Technical University on the Value of IBM storage in this high value IBM solution a part of the IBM Cloud strategy. Lloyd maintains a Subject Matter Expert status across the IBM Spectrum Storage Software solutions. You can follow Lloyd on Twitter @ldean0558 and LinkedIn Lloyd Dean.
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EMC Corporation (NYSE:EMC) today announced it has been positioned as a leader in the Forrester Wave™: Enterprise Open Systems Virtual Tape Library (VTL), Q1 2008 by Forrester Research, Inc. (January 31, 2008), an independent market and technology research firm. EMC achieved a position as a leader in the Forrester Wave report on virtual tape libraries based on the largest installed base of the EMC® Disk Library family of systems, its broad ecosystem interoperability. Virtual tape libraries emulate tape drives and work in conjunction with existing backup software applications, enabling fast backup and restoration of data by using high-capacity, low-cost disk drives.
EMC was the first major vendor in the open systems virtual tape library market as it introduced the EMC Disk Library in April 2004 and today is a leading provider of open systems virtual tape solutions, with systems that are designed for businesses and organizations of all sizes.
While the press release implies that "EDL equals VTL", Chuck tries to explain they are in fact very different. Here is an excerpt from his blog post:
Virtual Tape Libraries vs. Disk Libraries
As many of you know, VTLs have been around for a while. They use disk as a cache -- they buffer the incoming backup streams, do some housekeeping and stacking, then turn around and write tape efficiently. When you go to restore, you're usually coming back off of tape, unless the backup image in question is sitting in the disk cache.
Now, there is nothing wrong with the VTL approach, but it was conceived in a time when disks were horribly expensive. It was also pretty clear to many of us that disks were going to be a whole lot cheaper in the near future, and this fundamental assumption wouldn't be valid for much longer.
I kept thinking in terms of disk as a direct target for a backup application. No modifications to the backup application. Native speed of sequential disks for both backup and restore. Tape positioned as a backup to the backup. Use the strengths of the underlying array (e.g. CLARiiON) for performance, availability, management, etc.
We ended up calling the concept a "disk library" to differentiate from the VTLs that had come before it. It was a different value proposition and offering, based on the emergence of lower-cost disk media.
... It's nice to see we're at 1,100+ customers, and still going strong.
For those new to the blogosphere, there is a difference between "Press Releases" as formalcorporate communications versus "Blog Posts" which are informal opinions of the individual blogger, whichmay or may not match exactly the views of their respective employer.As we've learned many times before, one should not treat termslike "first" or "leader" in corporate press releases literally! Let's explore each.
Was EDL the first "open systems" Virtual Tape Library?
This is implied by the Forrester report. Chuck mentions the "VTLs that had came before it" in his blog, and many people are aware that IBM and StorageTek had introduced mainframe-attached VTLs in the 1990s. But what about VTL for "open systems"?
(Hold aside for the moment that IBM System zmainframe is an open system itself, with z/OS certified as a bona fide UNIX operating system by the [the Open Group] standards body. Most analysts and research firms usually refer only to the non-mainframe versions of UNIX and Windows. Alternative definitions for "open systems" can be foundin [Web definitions or Wikipedia]. I will assume Forrester meantnon-mainframe servers.)
IBM announced AIX non-mainframe attachment via SCSI connectivity to the IBM 3494 Virtual Tape Server (VTS) on Feb 16, 1999, with general availability in May 28, 1999. That's nearly FIVE YEARS before the April 2004 introduction of EDL. IBM VTS support for Sun Solaris and Microsoft Windows came shortly thereafter in November 2000, and support for HP-UX a bit later in June 2001. One of my 17 patents is for the software inside the IBM 3494 VTS, so like Chuck, I can takesome pride in the success of a successful product.
(I don't remember if StorageTek, which was subsequently acquired by Sun, had ever supported non-mainframe operating systems with their Virtual Storage Manager[VSM] offering, but if they did, I am sure it was also before EMC.)
Last week, another EMC blogger, BarryB (aka [the Storage Anarchist]),took me to task in comments on my post [IBM now supports 1TB SATA drives]. He felt that IBM should not claim support, given that the software inside the IBM System Storage N series is developed by NetApp. He compared this to the situation of HP and Sun re-badging the HDS USP-V disk system. If someone else wrote the software, BarryB opines, IBM should not claim credit for it. I tried to explain how IBM provides added value and has full-time employees dedicated to N series development and support, butdoubt I have changed his mind.
Why do I bring that up? Because the EMC Disk Library runs OEM software from FalconStor. Basically EMC is assembling a hardware/software solution with components provided from OEM suppliers. Hmmm? Sound familiar? Who is calling the kettle black?
If there is a clear winner here, it is FalconStor itself.Perhaps one of the worst kept industry secrets is that FalconStor software is also used in VTL offerings from Sun, Copan, and IBM, the latter embodied as the [IBM TS7520 Virtualization Engine] offering. If you like the concept of an EDL,but prefer instead one-stop shopping from an "information infrastructure" vendor, IBM can offer the TS7520 along with servers, software and services for a complete end-to-end solution.
Can EMC claim to be "a leader" in Virtual Tape Libraries?
During the measured quarter, IBM shipped its 10 millionth LTO-4 tape drive cartridge to Getty Images, the world's leading creator and distributor of still imagery, footage and multi-media products, as well as a recognized provider of other forms of premium digital content, including music. Getty Images is using the LTO-4 drives as part of a tiered infrastructure of IBM disk and tape solutions that help support the backup needs of their digital imagery;
IBM shipped more than 1,500 Petabytes of tape storage in Q3'07 alone;
During Q3'07, IBM shipped the 10,000th IBM System Storage TS3500 Tape Library. The TS3500 is a highly scalable tape library with support from 1 to 192 tape drives and up to 6,400 cartridge slots for open system, mainframe and virtual tape system attachment.
Let's take a look at the numbers. IBM has sold over 5,400 virtual tape libraries. Sun/STK has sold over 4,000 virtual tape libraries. Both are drastically more than the 1,100 mentioned in Chuck's post. Does IDC recognize EMC in third place? No, EMC chooses instead to declare EDL as disk arrays (probably toprop up their IDC "Disk Tracker" numbers), so they don't even earn an honorable mention under the virtual tape librarycategory. This of course includes the number of mainframe-attached models from IBM and Sun/STK. So, if EMC did call these tape systems instead, they might showup in third place, and as such EMC could claim to be "a leader" in much the same way an athlete can claim to be an "Olympic medalist" winning the bronze for third place. (If you limit thecount to just the FalconStor-based models from IBM, EMC, Sun and Copan, then EMC moves up to first or second, but then press release titles like "EMC a Leader in FalconStor-based non-mainframe Virtual Tape Libraries" can get too confusing.)
Chuck, if you are reading this, I feel you have every right to celebrate your involvement with the EDL. Despite having common software and hardware components, both IBM and EMC can rightfully declare their own unique value-add through their respective VTL offerings. Like the IBM N series, the EMC Disk Library is not diminished by the fact the software was written by someone else. BarryB might disagree.
Hello everyone! I am back, fully well-rested from a wonderful 3-week vacation touring the lovely state of Tennessee. Here's a quick recap:
(FCC Disclosure: I mention various companies and products in this blog post. I have no financial interested in any of them, nor have I received any compensation to mention or endorse them here.)
Our first stop was Lynchburg, TN, home of [Jack Daniel's], America's oldest whiskey distillery. Our tour guide, Ron (who both looked and sounded like [John Goodman]) took us first to see how they burn wood to make charcoal, then the natural water spring which supplies the iron-free water used for the whiskey. We then got a whiff of the mash at various stages of fermentation. Lastly, we had samples of Original No. 7, Gentleman's Jack, and Single Barrel.
(A word of caution: Domestic airlines only allow FIVE LITERS of Bourbon, Whiskey or Rum in your checked luggage. That is only six bottles at the 750ml size, of beverages that are between 24 to 70 percent alcohol by volume [ABV]. Anything above 70 percent is considered too flammable to take on the plane. Excess bottles can be custom packed and shipped, but can be quite expensive. Nearly everyone we met drove all the way to Tennessee instead of flying, and now I understand why.)
While in the area, we had a nice lunch at [Miss Mary Bobo's], a boarding house turned into a restaurant. They only serve one meal a day at 1pm, by reservation only. And we were paired up with eight others and served food "family style" a large round table with a [Lazy Susan].
Jack Daniel's is not the only attraction in the area. We also visited [Falls Mill], a grist mill that grinds corn, wheat and rye for the other distilleries. Mo and I visited [Prichard's Distillery], where they make Whiskey, Rye and Rum. We highly recommend their molasses-flavored "Sweet Lucy"!
We stopped at the famous historic landmark, the [Chattanooga Choo Choo], which was formerly a train station, and now renovated into a hotel. We asked to see the inside of one of the train cars converted into a hotel room.
Gatlinburg and Pigeon Forge
We stayed in a cabin in the [Smokey Mountains] near Gatlinburg. In addition to pleasant rides through the National park, we also walked around the small town, looking at all the shops and amusements.
The next town over is Pigeon Forge, and driving down the main parkway is like Las Vegas in a slightly alternate universe. One person called it the Redneck Riviera!
We spent two days at Dollywood theme park, named after its founder, famous country singer Dolly Parton. We arrived after 3pm the first day, so they gave us the second day free!
In addition to roller coaster rides, artisan shops and restaurants, we found zip lines! Mo and I put on harness, attached to a pulley, and zipped over roller coasters, trees and rivers throughout Dollywood park. It was a lot of fun!
We also went to Dolly Parton's other attraction: Stampede. This was a dinner show with horses. It was similar to the Excalibur show we saw in Las Vegas last year during the week of Edge 2013 Conference.
On our way from Gatlinburg, we stopped into Knoxville to have lunch with clients. We had a choice to make, we could either drive up into Kentucky and visit the distilleries in the Bourbon trail, or drive straight to Nashville and spend more time there. We opted for Nashville, saving the Bourbon trail for a future trip.
Our final stop was Nashville, known as Music City. Our hotel was on Broadway, walking distance between Vanderbilt University and the [honky-tonks] downtown.
We had purchased advanced tickets for the [Grand Ole Opry]. This is not your typical concert. Instead, you have no idea who will play until just a few days before. The three hour show had about a dozen different musical acts, some famous, some new to the country music scene.
We went to the Johnny Cash Museum. People with ticket stubs from the Grand Ole Opry get in for a discount!
Searching [TripAdvisor] for things to do in Nashville, I found [The Escape Game]. You pay them money to lock you up in a room with a bunch of strangers, and then collectively as a team you need to figure out how to escape by solving puzzles and clues.
Each room has different themes. First, we tried the "Underground Playground". You know that TV show [Are you Smarter than a Fifth Grader?] Well, the majority of our so-called team were not in this case, and after 60 minutes the referee told us we had failed and unlocked the door.
We had so much fun that we came back two days later to try a different room. This time we tried "The Heist" which is all about art theft. The strangers we were teamed up with were very motivated to get out of the room in time, and we succeeded, getting out in just 54 minutes!
Mo and I had a great time, but are glad to be back home!
Well, I'm going to take a two week break from blogging. Not because my clarification of storage terminology got me Marc Farley's finger wagging of shame.
No, I'm going on vacation.I'll be going to a third-world country, possibly outside the reaches of cell phones, e-mail and the internet, so I won't be blogging until I get back later this month. Since Clark Hodge has discovered a pattern that I am suspiciously close to massive power failures, I think it best not to tell people exactly where I am going.
So, until I get back, I leave you with a nice piece from Kirby at Storage Sanity who has discovered that IBMers are very nice.
Over the past ten years, my co-workers have asked to write a "guest post" on this blog. This time, Moshe Weiss, IBM Senior Manager, Development and Design, has offered the following post, not in his own voice, but in the voice of his "baby", the Hyper-Scale Manager software.
You might think this is a strange approach, but today we have robots that can dance, and cars that can drive themselves! If software could talk, this is what IBM Hyper-Scale Manager would say:
"I was born a year ago.
It wasn't an easy birth… there were many complications. In fact, so many, that I was almost prematurely born!
Most of my development, in preparation for labor and delivery, was done within the last 6 months of the overall 18 months. I was shaped and designed, and sometimes re-shaped, three times. Lots of assumptions had to be made in hopes to ease a successful delivery and help bring me to full term of the birthing process.
During my first year of maturity, I focused on learning how customers used me; what frustrated them the most, and what they loved or 'almost' loved, while still needing refinement and redesign.
The number of customers adopting me grew higher and higher, as did the number of complaints and bugs that I had to deal with, and my users’ frustrations and dislikes because I wasn't yet a complete solution and still had some missing features.
I was renewed four times! Each time of which improved me and made my senses better, faster, adding new capabilities that helped make me more approachable, intuitive and delightful.
Choosing how to renew, and what to add to each renewal, is not an easy task. Basically, it was about prioritizing user experience versus gaps that were deferred from my birth, versus differentiators to make me unique and sell more, versus features in my roadmap, versus investing huge efforts in my quality.
Each renewal was a complex process with lots of features and behaviors to add, while trying to make my customers’ life a bit easier, since features that were important to them were sometimes considered low priority.
But, there were also good times during my first year:
Huge customer adoption rate
100 new customers in two months!
Growing was a great thing and my parents were and are still so proud! But, like with most things, it came with a price - a lot of sustain issues from the field, requests for changes and bad feedback that I am hard to use and missing core elements.
Being a new baby in the Storage world is not a simple thing, as expectations are huge (mainly because of my successful elder brother, the XIV GUI) and I must quickly keep up with all of them.
Although, I am getting tons of good feedback for being revolutionary and unique. People are emotionally engaged with me, and being that I’m a baby, I love to see emotions!
Huge marketing efforts to put me center stage
However, because of some initial problems at the start -- I am a new product, remember? -- I was thrown out of multiple customer sites, and some sales/marketing guys just stopped believing in me. That made me sad.
My parents did a great job, though, in talking, explaining and demonstrating what I can do, together with what I can’t do now, but will do soon. This really helped in some areas, and customers began to see what my parents saw in me for so many years.
I’m really enthusiastic to hear what people will think of me when I’m two years old!
As part of the renewal I had four times during my first year, design elements were reconsidered, redesigned and rewritten to find the best solutions ever. No product has come even close to what I suggest to the world… I am so proud of myself!
Additionally, my parents wrote approximately 20 patents on my User Interface (UI) elements and User Experience (UX) concepts, which makes me extremely unique.
Prioritization of what goes in and what doesn't, especially during a time when fewer and fewer babysitters handled me during that year. It was a real challenge. Read my parent's post [How to drive forward an exhausted team?] for more details.
But my parents did it! They succeeded to add cool features like:
Filter analytics and free text, making the filter a great experience that everyone is using.
Great UX improvements like redesigning the tabs, adding right click menus, and adding more on-boarding enablers
Improving the dashboard.
Improving my core business, capacity management (four different times!), and still working on it.
Adding features that were initially deferred in my birth. Deferring features back then was the way to make my birth go smoother. Now, these missing features annoy people.
Improving quality dramatically, adding automation to the way people test me.
Adding differentiators, like the health widget, with more than 20 best practices that provide helpful tips to the customer when there’s a need to change something in their environment, to avoid future issues.
Continue to bring added values for the 'A-family'. I am monitoring: FlashSystem A9000/R, XIV and Spectrum Accelerate, both on and off premises. This added value makes for a family with the most powerful management solutions and experience."
If you are planning to attend the upcoming IBM Systems Technical University, Orlando Florida, May 22-26, There will also be a variety of hands-on labs. I recommend participating in the hands-on session to feel and witness the next release of IBM Hyper-Scale Manager.
You may not be the right person to ask but I am asking everyone so "How do you see hybrid disk drives?"
(For the record, I am not immediately related to Robert. At onepoint, "Pearson" was the 12th most common surname in the USA, but now doesn't even make the Top 100.)
Robert, I would like to encourage you and everyone else to ask questions, don't worry if I am the wrong person to ask, asprobably I know the right person within IBM. Some people have called me the "Kevin Bacon" of Storage,as I am often less than six degrees away from the right person, having worked in IBM Storage for over 20 years.
For those not familiar with hybrid drives, there is a good write-up in Wikipedia.
Unfortunately, most of the people I would consult on this question, such as those from Market Intelligence or Research, are on vacation for the holidays, so, Robert, I will have to rely on my trusted 78-card Tarot deck and answer you with a five-card throw.
Your first card, Robert, is the Hermit. This card represents "introspection". The best I/O is no I/O, which means that if applications can keep the information they need inside server memory, you can avoid the bus bandwidth limitations to going to external storage devices. Where external storage makes sense is when data is shared between servers, or when the single server is limited to a set amount of internal memory. So, consider maxing out the memory in your server first (IBM would be glad to sell you more internal memory!!!), then consider outside solid-state or hybrid devices. Windows for example has an architectural limit of 4GB.
Your second card, Robert, is the Four of Cups, representing "apathy".On the card, you see three cups together, with the fourth cup being delivered from a cloud. This reminds me thatwe have three storage tiers already (memory,disk,tape), and introducing a fourth tier into the mix may not garnermuch excitement. For the mainframe, IBM introduced a Solid-State Device, call the Coupling Facility, which can be accessed from multipleSystem z servers. It is used heavily by DFSMS and DB2 to hold shared information. However, given some customer's apathytowards Information Lifecycle Management which includes "tiered storage", introducing yet another tier that forcespeople to decide what data goes where may be another challenge.
Your third card, Robert, is the Chariot, which represents "Speed, Determination,and Will". In some cases, solid state disk are faster for reading, but can be slower for writing. In the case of ahybrid drive, where the memory acts as a front-end cache, read-hits would be faster, but read-misses might be slower.While the idea of stopping the drives during inactivity will reduce power consumption, spinning up and slowing downthe disk may incur additional performance penalties. At the time of this post, the fastest disk system remains the IBM SAN Volume Controller, based on SPC-1 and SPC-2 benchmarks in excess of those published for other devices.
Your fourth card, Robert, is the Eight of Pentacles, which represents"Diligence, Hard work". The pentacles are coins with five-sided stars on them, and this often represents money.Our research team has projected that spinning disk will continue to be a viable and profitable storage media for at least anothereight years.
Your fifth and last card, Robert, is the World, which normallyrepresents "Accomplishment", but since it is turned upside down, the meaning is reversed to "Limitation". Some Hybriddisks, and some types of solid state memory in general, do have limitations in the number of write cycles they can handle. For thoseunhappy with the frequency and slowness for rebuilds on SATA disk may find similar problems with hybrid drives.For that reason, businesses may not trust using hybrid drives for their busiest, mission-critical applications, but certainlymight use it for archive data with lower write-cycle requirements.
The tarot cards are never wrong, but certainly interpretations of the cards can be.
Several readers have asked me what is the difference between Hybrid Cloud and Multi-Cloud. The two phrases are used in various contexts, not just by IBM, but also by our competitors, as well as the press and industry analysts.
A hybrid cloud attempts to develop a single platform to run a specific Cloud workload. This single platform combines two or more of the following resources:
on-premise private Cloud
off-premise private Cloud
off-premise public Cloud
A Hybrid Cloud is like the United Nations peacekeeping force. A single force, with a single mission, representing the combined resources of many countries.
A Hybrid Cloud is a deployment model that might offer advantages over just using a Private Cloud, or just using a Public Cloud.
A practical example is Tennis Australia. For three weeks every January, they run the Australian Open, a tennis tournament, with over 4,000 employees, and millions of views to their website each day. For the rest of the year, they have only about 300 employees, and manage quite well to run smaller tournaments for high-school and college students, as well as plan for next year's event.
In this case, a Hybrid Cloud that combines perhaps two racks of an on-premise private Cloud, combined with the incredible power of IBM Cloud, gives them the variability and agility needed to run smoothly without wasting CAPEX on equipment they don't need.
Many "Hybrid Cloud" products focus on being the "glue" that combines two different resources together. This can be at the management layer, the data layer, the application layer, or the infrastructure layer.
In contrast, a Multi-Cloud represents a deployment strategy for different Cloud workloads. One workload might be better served on a Private Cloud, another workload might be better served on a Public Cloud, and a third workload, as we saw above, might benefit from the combined resources of a Hybrid Cloud.
In the past, people felt that all Cloud Service Providers were the same. Just as people buy gasoline from which ever gas station offers the lowest prices, many just chose their Cloud Service Provider based entirely on the costs involved. Loyalty can change the minute new price tables are published.
But today, Cloud Service Providers have made an effort to provide differentiation. For example, your Multi-Cloud might have three Hybrid Clouds. One cloud platform combines your on-premise Private Cloud with IBM Cloud, another combines your on-premise Private Cloud with Amazon Web Services, and a third combines your on-premise Cloud with Microsoft Azure.
In this case, a Multi-Cloud is like the various armed forces. You might deploy the Army for one mission, the Navy for another, and the Air Force or Marines for a third.
Many "Multi-Cloud" products focus on being versatile and multi-purpose. For example, the same FlashSystem 9100 that you deploy in your "Analytics Cloud" platform could also be useful for your "Docker Container Cloud" platform, or your "DevOPS Cloud" platform. IBM's various Multi-Cloud Solutions provide the additional software and services needed to complement the FlashSystem 9100 to pull this off.
Deciding to use a Multi-Cloud strategy is mostly a business decision. Deploying a Hybrid Cloud as one of your Multi-Cloud platforms could be a combination of business and technical decision.
While most of the post is accurate and well-stated, two opinions particular caught my eye. I'll be nice and call them opinions, since these are blogs, and always subject to interpretation. I'll put quotes around them so that people will correctly relate these to Hu, and not me.
"Storage virtualization can only be done in a storage controller. Currently Hitachi is the only vendor to provide this." -- Hu Yoshida
Hu, I enjoy all of your blog entries, but you should know better. HDS is fairly new-comer to the storage virtualization arena, so since IBM has been doing this for decades, I will bring you and the rest of the readers up to speed. I am not starting a blog-fight, just want to provide some additional information for clients to consider when making choices in the marketplace.
First, let's clarify the terminology. I will use 'storage' in the broad sense, including anything that can hold 1's and 0's, including memory, spinning disk media, and plastic tape media. These all have different mechanisms and access methods, based on their physical geometry and characteristics. The concept of 'virtualization' is any technology that makes one set of resources look like another set of resources with more preferable characteristics, and this applies to storage as well as servers and networks. Finally, 'storage controller' is any device with the intelligence to talk to a server and handle its read and write requests.
Second, let's take a look at all the different flavors of storage virtualization that IBM has developed over the past 30 years.
IBM introduces the S/370 with the OS/VS1 operating system. "VS" here refers to virtual storage, and in this case internal server memory was swapped out to physical disk. Using a table mapping, disk was made to look like an extension of main memory.
IBM introduces the IBM 3850 Mass Storage System (MSS). Until this time, programs that ran on mainframes had to be acutely aware of the device types being written, as each device type had different block, track and cylinder sizes, so a program written for one device type would have to be modified to work with a different device type. The MSS was able to take four 3350 disks, and a lot of tapes, and make them look like older 3330 disks, since most programs were still written for the 3330 format. The MSS was a way to deliver new 3350 disk to a 3330-oriented ecosystem, and greatly reduce the cost by handling tape on the back end. The table mapping was one virtual 3330 disk (100 MB) to two physical tapes (50 MB each). Back then, all of the mainframe disk systems had separate controllers. The 3850 used a 3831 controller that talked to the servers.
IBM invents Redundant Array of Independent Disk (RAID) technology. The table mapping is one or more virtual "Logical Units" (or "LUNs") to two or more physical disks. Data is striped, mirrored and paritied across the physical drives, making the LUNs look and feel like disks, but with faster performance and higher reliability than the physical drives they were mapped to. RAID could be implemented in the server as software, on top or embedded into the operating system, in the host bus adapter, or on the controller itself. The vendor that provided the RAID software or HBA did not have to be the same as the vendor that provided the disk, so in a sense, this avoided "vendor lock-in".Today, RAID is almost always done in the external storage controller.
IBM introduces the Personal Computer. One of the features of DOS is the ability to make a "RAM drive". This is technology that runs in the operating system to make internal memory look and feel like an external drive letter. Applications that already knew how to read and write to drive letters could work unmodified with these new RAM drives. This had the advantage that the files would be erased when the system was turned off, so it was perfect for temporary files. Of course, other operating systems today have this feature, UNIX has a /tmp directory in memory, and z/OS uses VIO storage pools.
This is important, as memory would be made to look like disk externally, as "cache", in the 1990s.
IBM AIX v3 introduces Logical Volume Manager (LVM). LVM maps the LUNs from external RAID controllers into virtual disks inside the UNIX server. The mapping can combine the capacity of multiple physical LUNs into a large internal volume. This was all done by software within the server, completely independent of the storage vendor, so again no lock-in.
IBM introduces the Virtual Tape Server (VTS). This was a disk array that emulated a tape library. A mapping of virtual tapes to physical tapes was done to allow full utilization of larger and larger tape cartridges. While many people today mistakenly equate "storage virtualization" with "disk virtualization", in reality it can be implemented on other forms of storage. The disk array was referred to as the "Tape Volume Cache". By using disk, the VTS could mount an empty "scratch" tape instantaneously, since no physical tape had to be mounted for this purpose.
Contradicting its "tape is dead" mantra, EMC later developed its CLARiiON disk library that emulates a virtual tape library (VTL).
IBM introduces the SAN Volume Controller. It involves mapping virtual disks to manage disks that could be from different frames from different vendors. Like other controllers, the SVC has multiple processors and cache memory, with the intelligence to talk to servers, and is similar in functionality to the controller components you might find inside monolithic "controller+disk" configurations like the IBM DS8300, EMC Symmetrix, or HDS TagmaStore USP. SVC can map the virtual disk to physical disk one-for-one in "image mode", as HDS does, or can also map virtual disks across physical managed disks, using a similar mapping table, to provide advantages like performance improvement through striping. You can take any virtual disk out of the SVC system simply by migrating it back to "image mode" and disconnecting the LUN from management. Again, no vendor lock-in.
The HDS USP and NSC can run as regular disk systems without virtualization, or the virtualization can be enabled to allow external disks from other vendors. HDS usually counts all USP and NSC sold, but never mention what percentage these have external disks attached in virtualization mode. Either they don't track this, or too embarrassed to publish the number. (My guess: single digit percentage).
Few people remember that IBM also introduced virtualization in both controller+disk and SAN switch form factors. The controller+disk version was called "SAN Integration Server", but people didn't like the "vendor lock-in" having to buy the internal disk from IBM. They preferred having it all external disk, with plenty of vendor choices. This is perhaps why Hitachi now offers a disk-less version of the NSC 55, in an attempt to be more like IBM's SVC.
IBM also had introduced the IBM SVC for Cisco 9000 blade. Our clients didn't want to upgrade their SAN switch networking gear just to get the benefits of disk virtualization. Perhaps this is the same reason EMC has done so poorly with its "Invista" offering.
So, bottom line, storage virtualization can, and has, been delivered in the operating system software, in the server's host bus adapter, inside SAN switches, and in storage controllers. It can be delivered anywhere in the path between application and physical media. Today, the two major vendors that provide disk virtualization "in the storage controller" are IBM and HDS, and the three major vendors that provide tape virtualization "in the storage controller" are IBM, Sun/STK, and EMC. All of these involve a mapping of logical to physical resources. Hitachi uses a one-for-one mapping, whereas IBM additionally offers more sophisticated mappings as well.
Last week, in Computer Technology Review's article [Tiering: Scale Up? Scale Out? Do Both], Mark Ferelli interviews fellow blogger Hu Yoshida, CTO of Hitachi Data Systems (HDS). Here's an excerpt:
"MF/CTR: A global cache should be required to implement that common pool that you’re talking about going across all tiers.
Hu/HDS: Right. So that is needed to get to all the resources. Now with our system, we can also attach external storage behind it for capacity so that as the storage ages out or becomes less active we can move it to the external storage. They would certainly have less performance capability, but you don’t need it for the stale data that we’re aging down. Right now we’re the only vendor that can provide this type of tiering.
If you look at other people who do virtualization like IBM’s SVC, the SVC has no storage within it because it’s sitting so if you attach any storage behind it, there is some performance degradation because you have this appliance sitting in front. That appliance is also very limited in cache and very limited in the number of storage boards on it. It cannot really provide you additional performance than what is attached behind it. And in fact, it will always degrade what is attached behind it because it’s not storage, where as our USP is storage and it has a global cache and it has thousands of port connections, load balancing and all that. So our front end can enhance existing storage that sits behind it."
This is not the first time I have had to correct Hu and others of misperceptions of IBM's SAN Volume Controller (SVC). This month marks my four year "blogoversary", and I seem to spend a large portion of my blogging time setting the record straight. Here are just a few of my favorite posts setting the record straight on SVC back in 2007:
Since day 1, SAN Volume Controllers has focused primarily on external storage. Initially, the early models had just battery-protected DRAM cache memory, but the most recent model of the SVC, the 2145-CF8, adds support for internal SLC NAND flash solid state drives. To fully appreciate how SVC can help improve the performance of the disks that are managed, I need to use some visual aids.
In this first chart, we look at a 70/30/50 workload. This indicates that 70 percent of the IOPS are reads, 30 percent writes, and 50 percent can be satisfied as cache hits directly from the SVC. For the reads, this means that 50 percent are read-hits satisfied from SVC DRAM cache, and 50 percent are read-miss that have to get the data from the managed disk, either from the managed disk's own cache, or from the actual spinning drives inside that managed disk array.
For writes, all writes are cache-hits, but some of them will be destaged to the managed disk. Typically, we find that a third of writes are over-written before this happens, so only two-thirds are written down to managed disk.
In this example, the SVC reduced the burden of the managed disk from 100,000 IOPS down to 55,000, which is 35,000 reads and 20,000 writes. Some have argued against putting one level of cache (SVC) in front of another level of cache (managed disk arrays). However, CPU processor designers have long recognized the value of hierarchical cache with L1, L2, L3 and sometimes even L4 caches. The cache-hits on SVC are faster than most disk system's cache-hits.
This is a Ponder curve, mapping millisecond response (MSR) times for different levels of I/O per second, named after the IBM scientist John Ponder that created them. Most disk array vendors will publish similar curves for each of their products. In this case, we see that 100,000 IOPS would cause a 25 millisecond response (MSR) time, but when the load is reduced to 55,000 IOPS, the average response time drops to only 7 msec.
To be fair, the SVC does introduce 0.06 msec of additional latency on read-misses, so let's call this 7.06 msec. This tiny amount of latency could be what Hu Yoshida was referring to when he said there was "some performance degradation". There are other storage virtualization products in the market that do not provide caching to boost performance, but rather just map incoming requests to outgoing requests, and these can indeed slow down every I/O they process. Perhaps Hu was thinking of those instead of IBM's SVC when he made his comments.
Of course, not all workloads are 70/30/50, and not every disk array is driven to its maximum capability, so your mileage may vary. As we slide down the left of the curve where things are flatter, the improvement in performance lowers.
IOPS before SVC
IOPS after SVC
MSR before SVC
MSR after SVC
Hitachi's offerings, including the HDS USP-V, USP-VM and their recently announced Virtual Storage Platform (VSP) sold also by HP under the name P9500, have similar architecture to the SVC and can offer similar benefits, but oddly the Hitachi engineers have decided to treat externally attached storage as second-class citizens instead. Hu mentions data that "ages out or becomes less active we can move it to the external storage." IBM has chosen not to impose this "caste" system onto its design of the SAN Volume Controller.
The SVC has been around since 2003, before the USP-V came to market, and has sold over 20,000 SVC nodes over the past seven years. The SVC can indeed improve performance of managed disk systems, in some cases by a substantial amount. The 0.06 msec latency on read-miss requests represents less than 1 percent of total performance in production workloads. SVC nearly always improves performance, and in the worst case, provides same performance but with added functionality and flexibility. For the most part, the performance boost comes as a delightful surprise to most people who start using the SVC.
To learn more about IBM's upcoming products and how IBM will lead in storage this decade, register for next week's webcast "Taming the Information Explosion with IBM Storage" featuring Dan Galvan, IBM Vice President, and Steve Duplessie, Senior Analyst and Founder of Enterprise Storage Group (ESG).
Last month, HP and Oracle jointly announced their new "Exadata Storage Server".This solution involves HP server and storage paired up with Oracle software, designed for Data Warehouse andBusiness Intelligence workloads (DW/BI).
I immediately recognized the Exadata Storage Server as a "me too" product, copying the idea from IBM's [InfoSphere Balanced Warehouse]which combines IBM servers, IBM storage and IBM's DB2 database software to accomplish this, but from a singlevendor, rather than a collaboration of two vendors.The Balanced Warehouse has been around for a while. I even blogged about this last year, in my post[IBMCombo trounces HP and Sun] when IBM announced its latest E7100 model. IBM offers three different sizes: C-class for smaller SMB workloads, D-class for moderate size workloads, and E-class for large enterprise workloads.
One would think that since IBM and Oracle are the top two database software vendors, and IBM and HP are the toptwo storage hardware vendors, that IBM would be upset or nervous on this announcement. We're not. I would gladlyrecommend comparing IBM offerings with anything HP and Oracle have to offer. And with IBM's acquisition of Cognos,IBM has made a bold statement that it is serious about competing in the DW/BI market space.
But apparently, it struck a nerve over at EMC.
Fellow blogger Chuck Hollis from EMC went on the attack, and Oracle blogger Kevin Closson went on the defensive.For those readers who do not follow either, here is the latest chain of events:
When it comes to blog fights like these, there are no clear winners or losers, but hopefully, if done respectfully,can benefit everyone involved, giving readers insight to the products as well as the company cultures that produce them.Let's see how each side fared:
Chuck implies that HP doesn't understand databases and Oracle doesn't understand server and storage hardware, socobbling together a solution based on this two-vendor collaboration doesn't make sense to him. The few I know who work at HP and Oracle are smart people, so I suspect this is more a claim againsteach company's "core strengths". Few would associate HP with database knowledge, or Oracle with hardware expertise,so I give Chuck a point on this one.
Of course, Chuck doesn't have deep, inside knowledge of this new offering, nor do I for that matter, and Kevin is patient enough to correct all of Chuck's mistaken assumptions and assertions. Kevin understands that EMC's "core strengths" isn't in servers or databases, so he explains things in simple enough terms that EMC employees can understand, so I give Kevin a point on this one.
If two is bad, then three is worse! How much bubble gum and bailing wire do you need in your data center? The better option is to go to the one company that offers it all and brings it together into a single solution: IBM InfoSphere Balanced Warehouse.
Are you going to the [IBM Edge 2015 conference]? This is IBM's premiere conference covering IBM System Storage, z Systems and POWER Systems.
Here are some secrets for winning prizes while you attend!
Sit in the first FIVE rows of the Techincal Kickoffs - Monday 8:30am
Funding has been approved to give out a few nice prizes. To be eligible, you need to show up on time, and sit in the first five rows of any of the following three Kickoffs. I will be in the one for Storage!
Attend sessions by Edge Event Sponsor companies
Brocade, Cisco and others often present lectures at Technical Edge, and they often give out prizes at those sessions, as part of their sponsorship to the event.
Take a "Selfie" with IBM z13 System mainframe
Yes, we will actually have a z13 System on display at the Solution Center for you to take pictures with. Post it on Instragram, Twitter, Facebook or your other favorite social media websites and be eligible to win prizes.
Get your handwriting analyzed with an IBM POWER8 system
Get your handwriting analyzed at the Solution Center and be eligible to win prizes.
Get your badge scanned at as many booths as you can at the Solution Center
Yes, this means you might get an email from the companies involved, but it will also add you to the list of people eligible for some raffles and drawings for prizes.
Participate in the #IBMEdgeHunt scavenger hunt!
Follow the Twitter hashtag #IBMEdgeHunt to see what else the "Hunt Organizers" have in store during the week!
I arrive Sunday afternoon! Below are some of the hashtags I will be using during the event. You can follow me on @az990tony Twitter handle.