So here we are in January, named after the two-faced Roman god Janus, who in their mythology was the god of gates and doors, and beginnings and endings.
-- Roger von Oech[Our "Janus-Like" Powers]
Well, it's 2008, which could mark the end to RAID5 and mark the beginnings of a new disk storagearchitecture. IBM starts the year with exciting news, acquiring new disk technology from a smallstart-up called XIV, led by former-EMCer Moshe Yanai. Moshe was ousted publicly in 2001 from hisposition as EMC's VP of engineering, and formed his own company. It didn't take long for EMC bloggersto poke fun at this already. Mark Twomey, in his StorageZilla blog, had mentioned XIV before back in August,[XIV], and again todayin [IBM Buys XIV].
The following is an excerpt from the [IBM Press Release]:
To address the new requirements associated with next generation digital content, IBM chose XIV and its NEXTRA™ architecture for its ability to scale dynamically, heal itself in the event of failure, and self-tune for optimum performance, all while eliminating the significant management burden typically associated with rapid growth environments. The architecture also is designed to automatically optimize resource utilization of all the components within the system, which can allow for easier management and configuration and improved performance and data availability.
"We are pleased to become a significant part of the IBM family, allowing for our unique storage architecture, our engineers and our storage industry experience to be part of IBM's overall storage business," said Moshe Yanai, chairman, XIV. "We believe the level of technological innovation achieved by our development team is unparalleled in the storage industry. Combining our storage architectural advancements with IBM's world-wide research, sales, service, manufacturing, and distribution capabilities will provide us with the ability to have these technologies tackle the emerging Web 2.0 technology needs and reach every corner of the world."
The NEXTRA architecture has been in production for more than two years, with more than four petabytes of capacity being used by customers today.
Current disk arrays were designed for online transaction processing (OLTP) databases. The focus was onusing fastest most expensive 10K and 15K RPM Fibre Channel drives, with clever caching algorithmsfor quick small updates of large relational databases. However, the world is changing, and peoplenow are looking for storage designed for digital media, archives, and other Web 2.0 applications.
One problem that NEXTRA architecture addresses is RAID rebuild. In a standard RAID5 6+P+S configuration of 146GB 10K RPM drives, the loss of one disk drive module (DDM) was recovered by reconstructing the data from parity of the other drives onto the spare drive. The process took46 minutes or longer, depending on how busy the system was doing other things. During this time,if a second drive in the same rank fails, all 876GB of data are lost. Double-drive failures are rare,but unpleasant when they happen, and hopefully you have a backup on tape to recover the data from.Moving to slower, less expensive SATA drives made this situation worse. The drives have highercapacity, but run at slower speeds. When a SATA drive fails in a RAID5 array, it could take severalhours to rebuild, and that is more time exposure for a second drive failure. A rebuild for a 750GBSATA drive would take five hours or more,with 4.5 TB of data at risk during the process if a second drive failure occurs.
The Nextra architecture doesn't use traditional RAID ranks or spare DDMs. Instead, data is carved up into 1MBobjects, and each object is stored on two physically-separate drives. In the event of a DDM loss, allthe data is readable from the second copies that are spread across hundreds of drives. New copies aremade on the empty disk space of the remaining system. This process can be done for a lost 750GB drive in under20 minutes. A double-drive failure would only lose those few objects that were on both drives, so perhaps1 to 2 percent of the total data stored on that logical volume.
Losing 1 to 2 percent of data might be devastating to a large relational database, as this could impactthe entire access to the internal structure. However, this box was designed for unstructuredcontent, like medical images, music, videos, Web pages, and other discrete files. In the event of a double-drivefailure, individual files would be recovered, such as with IBM Tivoli Storage Manager backup software.
IBM will continue to offer high-speed disk arrays like the IBM System Storage DS8000 and DS4800 for OLTP applications, and offer NEXTRA for this new surge in digital content of unstructured data. Recognizing this trend, diskdrive module manufacturers will phase out 10K RPM drives, and focus on 15K RPM for OLTP, and low-speedSATA for everything else.
Update: This blog post was focused on the version of XIV box available as of January 2008 that was built by XIV prior to the IBM acquisition. IBM has since made a major revision, made available August 2008 thataddresses a variety of workloads, including database, OLTP, email, as well as digital content and unstructuredfiles. Contact your IBM or IBM Business Partner for the latest details!
Bottom line, IBM continues to celebrate the new year, while the EMC folks in Hopkington, MA will continue to nurse their hangovers. Now that's a good way to start the new year!
technorati tags: Janus, two-faced, Roman god, Roger Von Oech, IBM, RAID5, XIV, EMC, Moshe Yanai, Mark Twomey, StorageZilla, NEXTRA, double-drive failure, rebuild, HDD, DDM, HDD, digital content, unstructured data
The Storage Architect
writes in his post:
Array-based replication does have drawbacks; all externalised storage becomes dependent on the virtualising array. This makes replacement potentially complex. To date, HDS have not provided tools to seamlessly migrate away from one USP to another (as far as I am aware). In addition, there's the problem of "all your eggs in one basket"; any issue with the array (e.g. physical intervention like fire, loss of power, microcode bug etc) could result in loss of access to all of your data. Consider the upgrade scenario of moving to a higher level of code; if all data was virtualised through one array, you would want to be darn sure that both the upgrade process and the new code are going to work seamlessly...
The final option is to use fabric-based virtualisation and at the moment this means Invista and SVC. SVC is an interesting one as it isn't an array and it isn't a fabric switch, but it does effectively provide switching capabilities. Although I think SVC is a good product, there are inevitably going to be some drawbacks, most notably those similar issues to array-based virtualisation (Barry/Tony, feel free to correct me if SVC has a non-disruptive replacement path).
I would argue that the IBM System Storage SAN Volume Controller (SVC) is more like the HDS USP, and less like the Invista. Both SVC and USP provide a common look and feel to the application server, both provide additional cache to external disk, both are able to provide a consistent set of copy services.
IBM designed the SVC so that upgrades can occur non-disruptively. You can replace the hardware nodes, one node at a time, while the SVC system is up and running, without disruption to reading and writing data on virtual disk. You can upgrade the software, one node at a time, while the SVC system is up and running, without disruption to reading and writing data on virtual disk. You can upgrade the firmware on the managed disk arrays behind the SVC, again, without disruption to reading and writing data on virtual disk.
More importantly, SVC has the ultimate "un-do" feature. It is called "image mode". If for any reason you want to take a virtual disk out of SVC management, you migrate over to an "image mode" LUN, and then disconnect it from SVC. The "image mode" LUN can then be used directly, with all the file system data in tact.
I define "virtualization" as technology that makes one set of resources look and feel like a different set of resources with more desirable characteristics. For SVC, the more desirable characteristics include choice of multi-pathing driver, consistent copy services, improved performance, etc. For EMC Invista, the question is "more desirable for whom?" EMC Invista seems more designed to meet EMC's needs, not its customers. EMC profits greatly from its EMC PowerPath multi-pathing driver, and from its SRDF copy services, so it appears to have designed a virtualization offering that:
- Continuesthe use of EMC Powerpath as a multi-pathing driver. SVC supports driversthat are provided at no charge to the customer, as well as those built-in to each operating system like MPIO.
- and, continuesthe use of Array-based copy services like SRDF of the underlying disk. SVC providesconsistent copy services regardless of storage vendor being managed.
A post from Dan over at Architectures of Control explains the anti-social nature of public benches. City planners, in an effort to discourage homeless people from sleeping on benches in parks or sidewalks, design benches that are so uncomfortableto use, that nobody uses them. These included benches made of metal that are too hot or too cold during certainmonths, benches slanted at an angle that dump you on the ground if you lay down, or benches that have dividers sothat you must be in an upright seated position to use.
This is not a disparagement of split-path switch-based designs. Rather, EMC's specific implementation appears to be designed for it to continuevendor lock-in for its multi-pathing driver, continuevendor lock-in for its copy services when used with EMC disk, and only provide slightly improved data migration capability for heterogeneous storage environments. Other switch-based solutions, such as those from Incipient or StoreAge, had different goals in mind.
Sadly, my IBM colleague BarryW and I have probably spent more words discussing Invista than all eleven EMC bloggers combined this year. While everyone in the industry is impressed how often EMC can sell "me, too" products with an incredibly large marketing budget, EMC appears not to have set aside funds for the Invista.
If a customer could design the ideal "storage virtualization" solution that would provide them the characteristics they desire the most from storage resources, it would not be anything like an Invista. While there are pros and cons between IBM's SVC and HDS's TagmaStore offerings, the reason both IBM and HDS are the market leaders in storage virtualization is because both companies are trying to provide value to the customer, just in different ways, and with different implementations.
technorati tags: IBM, storage, virtualization, SVC, SAN Volume Controller, Incipient, StoreAge, EMC, Invista, HDS, TagmaStore, USP, PowerPath, SRDF, vendor, lock-in, TagmaStore
When new technologies are introduced to the marketplace, it is normal for customers to be skeptical.
My sister is a mechanical engineer, so when she needs to configure a part or component, she candesign it on the computer, and then use a "Rapid Prototyping Machine"that acts like a 3D printer, to generate a plastic part that matches the specifications. Some machinesdo this by taking a hunk of plastic and cutting it down to the appropriate shape, and others use glue andpowder to assemble the piece.
But not everything is that simple. Harry Beckwith deals with the issue of selling services and software featuresin his book "Selling the Invisible". How do you sell a service before it is performed? How do you sell a softwarefeature based on new technology that the customer is not familiar with?
Our good friends over at NetApp, our technology partners for the IBM System Storage N series, developed a"storage savings estimator" tool that can provide good insight into the benefits of Advanced Single InstanceStorage (A-SIS) deduplication feature.
I decided to run the tool to analyze my own IBM Thinkpad C: drive (Windows operating system and programs) and D: drive ("My Documents" folder containing all my data files) to see how much storage savings thetool would estimate. Here are my results:
WINXP-C-07G (C: drive)Total Number of Directories: 1272Total Number of Files: 56265Total Number of Symbolic Links: 0Total Number of Hard Links: 41996Total Number of 4k Blocks: 2395884Total Number of 512b Blocks: 18944730Total Number of Blocks: 2395884Total Number of Hole Blocks: 290258Total Number of Unique Blocks: 1611792Percentage of Space Savings: 20.61Scan Start Time: Wed Sep 5 14:37:06 2007Scan End Time: Wed Sep 5 14:53:51 2007
WINXP-D-07H (D: drive)Total Number of Directories: 507Total Number of Files: 7242Total Number of Symbolic Links: 0Total Number of Hard Links: 11744Total Number of 4k Blocks: 3954712Total Number of 512b Blocks: 31610595Total Number of Blocks: 3954712Total Number of Hole Blocks: 3204Total Number of Unique Blocks: 3524605Percentage of Space Savings: 10.79Scan Start Time: Wed Sep 5 14:21:16 2007Scan End Time: Wed Sep 5 14:34:30 2007
I am impressed with the results, and have a better understanding of the way A-SIS works. A-SIS looks at every4kB block of data, and creates a "fingerprint", a type of hash code of the contents. If two blocks have different "fingerprints", then the contents are known to be different. If two blocks have the same fingerprint, it is mathematically possible for them to be unique in content, so A-SIS schedules a byte-for-byte comparison to be sure they are indeed the same. This might happen hours after the block is initially written to disk, but is a much safer implementation, and does not slow down the applications writing data.
(In an effort to provide support "real time" as data was being written, earlier versions of deduplication
had to either assume that a hash collision was a match, or take time to perform the byte-for-byte comparisonrequired during the write process. Doing this byte-for-byte comparison when the device is the busiest doingwrite activities causes excessive undesirable load on the CPU.)
The estimator tool runs on any x86-based Laptop, personal computer or server, and can scan direct-attached, SAN-attached, or NAS-attached file systems. If you are a customer shopping around for deduplication, ask your IBM pre-sales technical support, storage sales rep, or IBM Business Partner to analyze your data. Tools like this can help make a simple cost-benefit analysis: the cost of licensing the A-SIS software feature versus the amount of storage savings.
technorati tags: IBM, Rapid prototyping, 3D printer, Harry Beckwith, Selling the Invisible, IBM, NetApp, Advanced Single Instance Storage, A-SIS, deduplication, fingerprint, hash code, EMC, flaw, MD5, Centera
Sometimes, it's difficult to explain the products I manage to people outside the IT storage industry. How do you explain FCP vs. FICON, Giant Magnetoresistive (GMR) heads, the SMI-S interface, etc. enough to then explain how your job relates to those technologies. At least my friends and family read this blog, so they can somewhat understand some of the things I am working on. When I visit my folks on Sundays, we sometimes discuss items they read in my blog that week.
In addition to a "take your children to work day", we have discussed within IBM a "take your parents to work day", especially for the young new hires who have a hard time explaining what their new job is to the rest of their family.
Seth Godin points to a video ad to fill a job position and the confusion therein with the "recruiter" who just doesn't understand the job involved.
The problem is not just your parents, but any of your co-workers old enough to be parents who haven't bothered to keep up with the latest advancements in Web 2.0 technology. Here are some examples:
- A project leader working with a technology partner asked if me if there was a difference between a "blog" and a "wiki" and which should his team use. This was not a simple yes/no answer, and involved some explanation, conversation and understanding of what he was trying to accomplish.
- For one of my meetings, someone instant-messaged me asking where it was, was it "face-to-face" (F2F) or Conference call (CC). I replied back, "A2A w/CC" (avatar-to-avatar with voice over conference call). When you are meeting other avatars in-world in Second Life, it gets quite distracting having everyone typing away, with their hands and fingers moving furiously, so we use a conference call to complement our 3D interaction.
That's why I was very excited to seeLinden Lab announces voice beta in Second Life. It won't be fully ready until later this year, but adding voice to Second Life will greatly reduce the hurdles we now have trying to coordinate conference calls with in-world activity.
I realize not everyone can keep up with all the new and different technologies, but the social networking aspects of some of these new developments are worth looking into.
technorati tags: IBM, blog, wiki, social networking, technology, avatar, voice, Second Life, GMR, FICON, FCP, SMI-S
Modified by JeffAntley
Wrapping up my week's theme of "diversity", with posts on a diverse set of topics,today I will suggest ways to spendyour time while you are walking 10,000 steps per day, as recommended by the authorsof the book "You: On a Diet"
(If you thought this was about the 10,000 steps it might take to implement a storage solution, you should switch over to IBM as your storage vendor. For example, the DS3200 and DS3400 can beimplemented in as little as SIX steps. That's pretty cool.)
Blogs like Lifehacker are an excellent resource for neat littletips and tricks to help you throughout your day, like how to use your iPod, cell phone or computer better, for example. These suggestions are based on the idea that you can walk your 10,000 steps with access to an iPod and cell phone.
- Learning a language
- ... or refreshing yourself on a language you might not have spoken in a while. In addition to formal audio-based lessons from Pimsleur, there are podcasts you can get for various languages. In preparation for my upcoming trip to Japan and China, I have been listening to JapanesePod101.com and ChinesePod.com which have quick lessons that complement the formal training.This Lifehacker postindicates there are similar ones for French, Spanish, Italian, and Brazillian Portuguese.
- Practicing your presentation
- Walking while practicing your 30-60 minute presentation would be good exercise.MicroPersuasion explains how to turn your iPod into the ultimate PowerPoint accessory, and this article in PlayListmag.com providesthe steps to get a PowerPoint presentation onto your iPod. I did this, and the slides are found underPhotos->Photo Library. The images are small, but heck, they are your charts and you should recognize themwell enough to remind yourself what to say on each slide.Also, I am able to record my practice sessions using MP3 Recorder and listen as I page through each slide. (In theory, you can use your iPod to present your slides to your audience, plugging the iPod directly into the laptop projector, instead of a laptop, using cables available at your local Apple store, and use the iPod controls as your forward/backward remote.)
- Working your To-Do list
- You can download your to-do list to your iPod. I use BackPackIt from 37 Signals. You can sign up for a free account, or upgrade to a paid account, and have anamazingly simple browser-based tool to develop your to-do lists, one for each project or aspect of your life. Oncedone, the list can be emailed to you as plain text. Enable your iPod as an "external disk drive" and copy this text file to your NOTES directory on the iPod drive. Voila! You can now read your to-do list! (I could also send it to my cell phone, using firstname.lastname@example.org, but I find the iPod easier to read and navigate)
Think of something to add? Send an email from your cell phone. With BackPackit, I can send an email that will directly add my text as a note or todo list item. On my phone, this is simply sending a text message to "500" with text like:
"email@example.com todo # buy bread".The hash mark (#) separates the subject line from the body of the email, and this is how Backpackit knows its a todo item or a note. If you pre-program the huge email address in advance on your phone, then it isn't as bad as it looks. It will be on your packpackit page the next time you log in.
Well, that's three suggestions. The next time you complain that there is no time to walk, you now have no excuse.
technorati tags: walking, LifeHacker, MicroPersuasion, IBM, DS3200, DS3400, PowerPoint, iPod, Backpackit, tmomail
I found this item today on the blogosphere: EMC-HP Storage Race Heats Up
In general, people agree that IBM, HP and EMC are the top three vendors in storage,with HDS, Sun and Dell rounding out the top six.
The fun begins when a respected analyst like IDC Corp. publishes their calculations,and individual vendors re-swizzle the results because they are not happy with theirfindings.
I thought it would be helpful to illustrate how this all works. First, you need to comeup with a defintion of what you are going to count. You could count units sold, revenue dollars, or capacity Terabytes, or some other generally accepted metric.
Next, you need to define what's in and what's out. For example, you can say "storage"which would include both disk drives and tape drives, both internal to servers, orexternal to servers, or you can choose a more narrow definition, say external disksystems, which might suit you better if you aren't in the tape business, and don't sell servers.
By some definitions, my Apple iPod, Motorolla cell phone, and Canon digital camera,could all be counted as external disk systems, as they all connect via USB cableto my IBM laptop, and act like a disk drive to my Windows operating system, allowingme to read and write data back and forth. It is necessary to define exactly what you plan to include,and what to exclude, based on the reported numbers available.
The last rule is that nothing gets double-counted. In our complicated industry ofmanufacturers and vendors, sometimes storage is manufactured by one company, but soldby another, typically under the vendor's brand, not the manufacturer's brand. Youcan either count manufactured units, or vendor units, but you can't mix and match.
IBM is both manufacturer and vendor. However, IDC only counts vendor units, so storagemanufactured by someone else, but sold by IBM is counted as IBM, and storage manufacturedby IBM but branded by someone else goes to that other vendor. Likewise, HP and Sun re-brandHitachi storage, and Dell re-brands EMC storage.
EMC would like to treat all EMC-manufactured storage re-branded by Dell as EMC vended storage,so that it can move up in the ratings. But Dell wants to count it too, so that it can appearin the top six. You can't have it both ways.
But are these ratings just "bragging rights"? Not always. When big purchases are planned fornew projects, or a client decides its time to throw out the current vendor and shop for a newone, the ratings could influence that decision. In that regard, IDC 4Q05 Storage Tracker reportedIBM as number one over all in storage hardware at the end of 2005, which includes both internal and external disk systems, as well as tape drives sold under the IBM brand, based on dollar revenues. By this method of counting, HP came in at number 2, EMC at number 3, and the rest round out thetop six as before.
In the end, this is just one factor when deciding which brand to choose for your storage needs.
technorati tags: IBM, HP, EMC, Dell, Sun, IDC, Apple, iPod, Motorolla, Canon, USB, laptop
This month (September, 2006) marks our 50th anniversary of the disk system. The first disk system was the 350 Disk Storage Unit, designed to attach to the IBM 305 RAMAC mainframe computer, both introduced to the world in September, 1956.
Read more about it
Has EMC stooped so low that they have to resort to Hitachi math for their latest performance claims?
Readers might remember that just a few months ago, I had a blog post [Is this what HDS tells our mainframe clients?] pointing out the outlandish comparison Hitachi was using in their presentations. Their response was to cover it up, forcing me to follow up with my post [The Cover-up is worse than the original crime]. To their credit, they eventually removed the false and misleading information from their materials.
Now an avid reader of my blog has brought this to my attention. Apparently,
EMC has been showing customers a presentation
[Accelerating Storage Transformation with VMAX and VPLEX] with false and misleading comparison claims between IBM DS8000, HDS VSP and EMC VMAX 40K disk system performance.
(FTC Disclosure: This would be a good time to remind my readers that I work for IBM and own IBM stock. I do not endorse any of the EMC or HDS products mentioned in this post, and have no financial affiliation or investments directly with either EMC nor HDS. I am basing my information solely on the presentation posted on the internet and other sources publicly available, and not on any misrepresentations from EMC speakers at the various conferences where these charts might have been shown.)
The problem with misinformation is that it is not always obvious. The EMC presentation is quite pretty and professional-looking. It is the typical slick, attention-getting, low-content, over-simplified marketing puffery you have come to expect from EMC. There are two slides in particular that I have issue with.
This first graphic implies that IBM and HDS are nearly tied in performance, but that EMC VMAX 40K has nearly triple that bandwidth. Overall the slide has very little detail. That makes it difficult to determine what exactly is being claimed and whether a fair comparison is being made.
- The title claims that VMAX 40K is "#1 in High Bandwidth Apps". Only three disk systems are shown so the claim appears to be relative to only the three systems. The wording "High Bandwidth Apps" is confusing considering the cited numbers are for disk systems and no application is identified. By comparison, IBM SONAS can drive up to 105 GB/sec sequential bandwidth, nearly double what EMC claims for its VMAX 40K, so EMC is certainly not even close to #1.
- Is the workload random or sequential? That is not easy to determine. The use of "GB/s" along with the large block size of 128KB implies the I/O workload is sequential, which is great for some workloads like high performance computing, technical computing and video broadcasts. Random workloads, on the other hand, are usually measured in I/Os per second (IOPS) with a block size ranging 4KB to 64KB. (I am assuming the 128K blocks refers to 128KB block size, and not reading the same block of cache 128,000 times.)
- The slide states "Maximum Sustainable RRH Bandwidth 128K Blocks". The acronym "RRH" is not defined; but I suspect this refers to "random read hits". For random workloads, 100 percent random read hits from cache represents one corner of the infamous "four corners" test. Real-world workloads have a mix of reads and writes, and a mix of cache hits and cache misses. It is also unclear whether the hits are from standard data cache or from internal buffers in adapters (perhaps accessing the same blocks repeatedly) or something else. So is this really for a random workload, or a sequential workload?
(The term "Hitachi Math" was coined by an EMC blogger precisely to slam Hitachi Data Systems for their blatant use of four-corners results, claiming that spouting ridiculously large, but equally unrealistic, 100 percent random read hit results don't provide any useful information. I agree. There are much better industry-standard benchmarks available, such as SPC-1 for random workloads, SPC-2 for sequential workloads, and even benchmarks for specific applications, that represent real-world IT environments. To shame HDS for their use of four-corners results, only for EMC themselves to use similar figures in their own presentation is truly hypocritical of them!)
- The IBM system is identified as "DS8000". DS8000 is a generic family name that applies to multiple generations of systems first introduced in 2004. The specific model is not identified, but that is critical information. Is this a first generation DS8100, or the latest DS8800, or something in between?
The slide says "Full System Configs", but that is not defined and configuration details are not identified. Configuration details, also critical information in assessing system performance capabilities, are not specified. If the EMC box costs seven times more than IBM or HDS, would you really buy it to get 3x more performance? Is the EMC packed with the maximum amount of SSD? Were there any SSD in the IBM or HDS boxes to match?
The source of the claimed IBM DS8000 performance numbers is not identified. Did they run their own tests? While I cannot tell, the VMAX may have been configured with 64 Fibre Channel 8Gbps host connections. In that case each channel is theoretically capable of supporting about 800 MB/s at 100% channel utilization. Multiplying 64 x 800MB/s = 51.2GB/s, so did EMC just do the performance comparison on the back of a napkin, assuming there are no other bottlenecks in the system? Even then, I would not round up 51.2 to 52!
- Response times were not identified. For random I/Os, response time is a very important metric. It is possible that the Symmetrix was operating with some resources at 100% utilization to get the highest GB/s result, but that would likely make I/O response times unacceptable for real-world random I/O workloads.
IBM and HDS have both published Storage Performance Council [SPC] industry-standard performance benchmarks. EMC has not published any SPC benchmarks for VMAX systems. If EMC is interested in providing customers with audited, detailed performance information along with detailed configuration information, all based on benchmarks designed to represent real-world workloads, EMC can always publish SPC benchmark results as IBM and other vendors have done. In past blog fights, EMC resorts to the excuse that SPC isn't perfect, but can they really argue that vague and unrealistic claims cited in its presentation are better?
The second graphic is so absurd, you would think it came directly from Larry Ellison at an Oracle OpenWorld keynote session. EMC is comparing a configuration with VMAX 40K plus an EMC VFCache host-side flash memory cache card to a configuration with an IBM and HDS disk system without host-side flash memory cache also configured. The comparison is clearly apples-to-oranges. Other disk system configuration details are also omitted.
FAST VP is EMC's name for its sub-volume drive tiering feature, comparable to IBM Easy Tier and Hitachi's Dynamic Tiering. The graph implies that IBM and HDS can only achieve a modest increment improvement from their sub-volume tiering. I beg to differ. I have seen various cases where a small amount of SSD on IBM DS8000 series can drastically improve performance 200 to 400 percent.
The "DBClassify" shown on the graph is a tool run as part of an EMC professional services offering called Database Performance Tiering Assessment, makes recommendations for storing various database objects on different drive tiers based on object usage and importance. Do you really need to pay for professional services? With IBM Easy Tier, you just turn it on, and it works. No analysis required, no tools, no professional services, and no additional charge!
- VFCache is an optional product from EMC that currently has no integration whatsoever with VMAX. A fair comparison would have included a host-side flash memory cache (from any vendor) when the IBM or HDS storage system was configured. Or leave it out altogether and just focus on the sub-volume tiering comparison.
Keep in mind that EMC's VFCache supports only selected x86-based hosts. IBM has published a [Statement of Direction] indicating that it will also offer this for Power systems running AIX and Linux host-side flash memory cache integrated with DS8000 Easy Tier.
I feel EMC's claims about IBM DS8000 performance are vague and misleading. EMC appears to lack the kind of technical marketing integrity that IBM strives to attain.
Since EMC is not able or willing to publish fair and meaningful performance comparisons, it is up to me to set the record straight and point out EMC's failings in this matter.
Reminder: It's not to late to register for my Webcast "Solving the Storage Capacity Crisis" on Tuesday, September 25. See my blog post [Upcoming events in September] to register!
technorati tags: IBM, DS8000, DS8800, HDS, VSP, EMC, VMAX, Symmetrix, VFCache, Easy Tier, FAST VP
Can Structured Query Language [SQL] be considered a storage protocol?
Several months ago, I was asked to review a book on SQL, titled appropriately enough "The Complete Idiot's Guide to SQL", by Steven Holzner, Ph.D. As a published author myself, I get a lot of these requests, and I agreed in this case, given that SQL was invented by IBM, and is a good fundamental skill to have for Business Analytics and Database Management.
(FTC Disclosure: I work for IBM but was not part of the SQL development team. I was provided a copy of this book for free to review it. I was not paid to mention this book, nor told what to write. I do not know the author personally nor anyone that works for his publicist. All of my opinions of the book in this blog post are my own.)
Despite an agreed-upon standard for SQL, each relational database management system (RDBMS) has decided to customize it for their own purposes. First, SQL can be quite wordy, so some RDBMS have made certain keywords optional. Second, RDBMS offer extra features by adding keywords or programming language extentions, options or parameters above and beyond what the SQL standard calls for. Third, the SQL standard has changed over the years, and some RDBMS have opted to keep some backward compatibility with their prior releases. Fourth, some RDBMS want to discourage people from easily porting code from one RDBMS to another, known in the industry as vendor lock-in.
Throughout my career, I have managed various databases, including Informix, DB2, MySQL, and Microsoft SQL Server, so I am quite familiar with the differences in SQL and the problems and implications that arise.
Most authors who want to write about SQL typically make a choice between (a) stick to the SQL standard, and expect the reader to customize the examples to their particular DBMS; or (b) stick to a single RDBMS implemenation, and offer examples that may not work on other RDBMS.
I found the book "The Complete Idiot's Guide to SQL" covered the basics quite well, but with an odd twist. The basics include creating databases and tables, defining columns, inserting and deleting rows, updating fields, and performing queries or joins. The odd twist is that Steven does not make the typical choice above, but rather shows how the various DBMS are different than standard SQL syntax, with actual working examples for different RDBMS.
You might be thinking to yourself that only an idiot would work in a place that had to require knowledge of multiple RDBMS. The sad truth is that most of the medium and large companies I speak to have two or more in production. This is either through acquisitions, or in some cases, individual business units or departments implementing their own via the [Shadow IT].
(For those who want to learn SQL and try out the examples in this book, IBM offers a free version of DB2 called [DB2-C Express] that runs on Windows, Linux, Mac OS, and Solaris.)
Last week, while I was in Russia for the [Edge Comes to You] event, I was interviewed by a journalist from [Storage News] on various topics. One question stuck me as strange. He asked why I did not mention IBM's acquisition of Netezza in my keynote session about storage. I had to explain that Netezza was not in the IBM System Storage product line, it is in a different group, under Business Analytics, where it belongs.
While it is true that Netezza can store data, because it has storage components inside, the same could also be said about nearly every other piece of IT equipment, from servers with internal disk, to digital cameras, smart phones and portable music players. They can all be considered storage devices, but doing so would undermine what differentiates them from one another.
Which brings me back to my original question: Should we consider SQL to be a storage protocol? For the longest time, IT folks only considered block-based interfaces as storage protocols, then we added file-based interfaces like CIFS and NFS, and we also have object-based interfaces, such as IBM's Object Access Method (OAM) and the System Storage Archive Manager (SSAM) API. Could SQL interfaces be the next storage protocol?
Let me know what you think on this. Leave a comment below.
technorati tags: IBM, SQL
Tonight PBS plans to air Season 38, Episode 6 of NOVA, titled [Smartest Machine On Earth]. Here is an excerpt from the station listing:
"What's so special about human intelligence and will scientists ever build a computer that rivals the flexibility and power of a human brain? In "Artificial Intelligence," NOVA takes viewers inside an IBM lab where a crack team has been working for nearly three years to perfect a machine that can answer any question. The scientists hope their machine will be able to beat expert contestants in one of the USA's most challenging TV quiz shows -- Jeopardy, which has entertained viewers for over four decades. "Artificial Intelligence" presents the exclusive inside story of how the IBM team developed the world's smartest computer from scratch. Now they're racing to finish it for a special Jeopardy airdate in February 2011. They've built an exact replica of the studio at its research lab near New York and invited past champions to compete against the machine, a big black box code -- named Watson after IBM's founder, Thomas J. Watson. But will Watson be able to beat out its human competition?"
Craig Rhinehart offers
[10 Things You Need to Know About the Technology Behind Watson].
An artist has come up with this clever
Dr. Jon Lenchner from IBM Research has a series of posts on
[How Watson "sees", "hears", and "speaks"] and [Selected Nuances].
Like most supercomputers, Watson runs the Linux operating system. The system runs 2,880 cores (90 IBM Power 750 servers, four sockets each, eight cores per socket) to achieve 80 [TeraFlops]. TeraFlops is the unit of measure for supercomputers, representing a trillion floating point operations. By comparison, Hans Morvec, principal research scientist at the Robotics Institute of Carnegie Mellon University (CMU) estimates that the [human brain is about 100 TeraFlops]. So, in the three seconds that Watson gets to calculate its response, it would have processed 240 trillion operations.
Several readers of my blog have asked for details on the storage aspects of Watson. Basically, it is a modified version of IBM Scale-Out NAS [SONAS] that IBM offers commercially, but running Linux on POWER instead of Linux-x86. System p expansion drawers of SAS 15K RPM 450GB drives, 12 drives each, are dual-connected to two storage nodes, for a total of 21.6TB of raw disk capacity. The storage nodes use IBM's General Parallel File System (GPFS) to provide clustered NFS access to the rest of the system. Each Power 750 has minimal internal storage mostly to hold the Linux operating system and programs.
When Watson is booted up, the 15TB of total RAM are loaded up, and thereafter the DeepQA processing is all done from memory. According to IBM Research, "The actual size of the data (analyzed and indexed text, knowledge bases, etc.) used for candidate answer generation and evidence evaluation is under 1TB." For performance reasons, various subsets of the data are replicated in RAM on different functional groups of cluster nodes. The entire system is self-contained, Watson is NOT going to the internet searching for answers.
On ZDnet, Steven J. Vaughan-Nichols welcomes our new [Linux Penguin Jeopardy overlords]. I have to say I share his enthusiasm!
technorati tags: IBM, Nova, Watson, #ibmwatson, Jeopardy, POWER7, p750, supercomputer, TeraFlops, disk, SONAS, GPFS, SAS, Craig Rhinehart, Jon Lenchner, Hans Morvec, Carnegie Mellon University, CMU